UNITED STATES DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

NATIONAL MARINE FISHERIES SERVICE

Northwest Region 

7600 Sand Point Way N.E., Bldg. 1 

Seattle, WA 98115 

Refer to NMFS No: 

2011/06017 July 10, 2012 

Christine B. Reichgott 

Unit Manager 

Environmental Review & Sediment Management 

U.S. Environmental Protection Agency, Region 10 

1200 Sixth Avenue, Suite 900 

Seattle, Washington 98101-3140 

Re: Endangered Species Act Biological Opinion and Magnuson-Stevens Fishery 

Conservation and Management Act Essential Fish Habitat Response for the 

Environmental Protection Agency Designation of the North and South Yaquina River 

Ocean Disposal Material Dredged Sites, Pacific Ocean, Lincoln County, Oregon 

Dear Ms. Reichgott: 

The enclosed document contains a biological opinion (opinion) prepared by the National Marine 

Fisheries Service (NMFS) pursuant to section 7(a)(2) of the Endangered Species Act (ESA) on 

the effects of Environmental Protection Agency’s (EPA) designation of the North and South 

Yaquina River Ocean Disposal Material Dredged Sites (ODMD) under their authority found in 

section 102(c) of the Marine Protection, Research and Sanctuaries Act, as amended (MPRSA), 

33 U.S.C. §§ 1401 to 1445 near the mouth of the Yaquina River, Lincoln County, Oregon. 

Included in this designation is the adoption of a Site Management and Monitoring Plan (SMMP). 

In this opinion, NMFS concludes that the proposed action is not likely to adversely affect five 

species of Chinook salmon, two species of coho salmon, four species of marine turtles, Southern 

Resident killer whales (Orcinus orca) eastern distinct population segment (DPS) Steller sea lions 

(Eumotopias jubatus), and five other species of marine mammals. All of these species are listed 

under the Endangered Species Act. 

The NMFS also concluded that the proposed action is not likely to jeopardize the continued 

existence of Oregon Coast coho salmon (Oncorhynchus kisutch), southern DPS North American 

green sturgeon (Acipenser medirostris), southern DPS Pacific eulachon (Thaleichthys pacificus), 

or result in the destruction or adverse modification of designated critical habitat for southern 

DPS North American green sturgeon. 
The adverse effects identified in this opinion that NMFS is reasonably certain will occur are the 

result of the indirect effects of subsequent Federal actions carried out by the United States Army 

Corps of Engineers (Corps) and other entities carrying out dredging and disposal. The EPA 

expects the ODMD sites will be used in the future for disposal of material dredged by other 

public or private entities (e.g. the U.S. Coast Guard, Port of Yaquina, Port of Toledo) in 

accordance with section 103 of the MPRSA. These disposals would require section 103 permits 

(which could be multiple year authorizations up to 7 years) from the Regulatory Branch of the 

Corps and EPA concurrence. Individual permits are publicly noticed and require other Federal 

consultations (e.g. ESA, EFH) and authorizations (e.g. water quality certification). The EPA’s 

action here does not authorize and will not itself result in disposal of any dredged materials. 

Therefore, although NMFS anticipates indirect effects from EPA’s action, it does not anticipate 

any take will be caused by the site designation and adoption of the SMMP. Any further analysis 

of the effects of disposal of dredged material at the disposal site and issuance of an incidental 

take statement will be prepared when the disposal permit is requested by the action agency. 

This document also includes the results of our analysis of the action’s likely effects on essential 

fish habitat (EFH) pursuant to section 305(b) of the Magnuson-Stevens Fishery Conservation and 

Management Act (MSA), and includes two conservation recommendations to avoid, minimize, 

or otherwise offset potential adverse effects on EFH. These conservation recommendations are 

not a subset of the ESA take statement’s terms and conditions. Section 305(b) (4) (B) of the 

MSA requires Federal agencies to provide a detailed written response to NMFS within 30 days 

after receiving these recommendations. 

If the response is inconsistent with the EFH conservation recommendations, the Federal action 

agency must explain why the recommendations will not be followed, including the scientific 

justification for any disagreements over the effects of the action and the recommendations. In 

response to increased oversight of overall EFH program effectiveness by the Office of 

Management and Budget, NMFS established a quarterly reporting requirement to determine how 

many conservation recommendations are provided as part of each EFH consultation and how 

many are adopted by the action agency. Therefore, we request that in your statutory reply to the 

EFH portion of this consultation, you clearly identify the number of conservation 

recommendations accepted. 

Please direct questions regarding this opinion to Jeff Young, fishery biologist in the Oregon 

Coast Branch of the Oregon State Habitat Office, at 541.957.3389. 

 Sincerely, 

 William W. Stelle, Jr. 

 Regional Administrator 

cc: Bridgette Lohrman, EPA 

 Kate Groth, Corps 
Endangered Species Act Biological Opinion 

and 

Magnuson-Stevens Fishery Conservation and Management Act 

Essential Fish Habitat Response 

for the 

EPA Designation of the North and South Yaquina River Ocean Disposal Material Dredged Sites 

Pacific Ocean, Lincoln County, Oregon 

NMFS Consultation Number: 2011/06017

Federal Action Agency: U.S. Environmental Protection Agency 

Affected Species and Determinations: 

ESA-Listed Species ESA 

Status 

Is the action likely 

to adversely affect 

this species or its 

critical habitat? 

Is the Action 

likely to 

jeopardize this 

species? 

Is the action likely to 

destroy or adversely 

modify critical habitat 

for this species? 

Oregon Coast coho salmon T Y N N 

Southern DPS green sturgeon T Y N N 

Southern DPS Pacific eulachon T Y N N 

Southern Oregon/Northern California 

Coast coho salmon T N N N 

Lower Columbia R. Chinook salmon T N N N 

Upper Columbia R. Chinook salmon T N N N 

Upper Willamette R. Chinook salmon T N N N 

Snake R. spr/sum Chinook Salmon T N N N 

Snake R. fall Chinook salmon T N N N 

Eastern DPS Steller sea lion T N N N 

Blue whale E N N N/A 

Sei whale E N N N/A 

Sperm whale E N N N/A 

Fin whale E N N N/A 

Humpback whale E N N N/A 

Southern Resident Killer Whale E N N N 

Green turtle T N N N 

Leatherback turtle E N N N 

Loggerhead turtle T N N N 

Olive Ridley turtle E N N N/A 

 

Fishery Management Plan that Describes EFH in the 

Action Area 

Would the action adversely 

affect EFH? 

Are EFH conservation 

recommendations provided? 

Pacific Coast salmon Y Y 

Coastal pelagics species Y Y 

Pacific Coast groundfish Y Y 
Consultation 

Conducted By: National Marine Fisheries Service 

 Northwest Region 

Issued by: ___________________ 

 William W. Stelle, Jr. 

 Regional Administrator 

Date: July 10, 2012 
-iTABLE OF CONTENTS 

1. INTRODUCTION ...................................................................................................................... 1

1.1 Background ........................................................................................................................... 1

1.2 Consultation History ............................................................................................................. 1

1.3 Proposed Action .................................................................................................................... 2

1.4 Action Area ........................................................................................................................... 6

2. ENDANGERED SPECIES ACT BIOLOGICAL OPINION AND INCIDENTAL TAKE 

STATEMENT ................................................................................................................................. 9

2.1 Introduction to the Biological Opinion ................................................................................. 9

2.2 Rangewide Status of the Species and Critical Habitat ........................................................ 11

2.2.1 Status of the Species ................................................................................................ 12

2.2.2 Status of the Critical Habitat .................................................................................... 24

2.3 Environmental Baseline ...................................................................................................... 26

2.4 Effects of the Action on the Species and Designated Critical Habitat ............................... 33

2.4.1 Effects to the Environment ...................................................................................... 33

2.4.2 Effects to ESA-listed species ................................................................................... 37

2.4.3 Effects to Critical Habitat ........................................................................................ 50

2.5 Cumulative Effects.............................................................................................................. 52

2.6 Integration and Synthesis .................................................................................................... 52

2.6.1 ESA-listed Species ................................................................................................... 52

2.6.2 Critical Habitat ......................................................................................................... 53

2.7 Conclusion .......................................................................................................................... 53

2.8. Incidental Take Statement .................................................................................................. 53

2.8.1 Amount or Extent of Take ....................................................................................... 54

2.9. Conservation Recommendations ....................................................................................... 54

2.10 Reinitiation of Consultation .............................................................................................. 55

2.11 “Not Likely to Adversely Affect” Determinations ........................................................... 55

2.11.1 ESA-listed Fish Species ......................................................................................... 55

2.11.2 ESA-listed Marine Mammals ................................................................................ 56

2.11.3 ESA-listed Marine Turtles ..................................................................................... 57

2.11.4 Leatherback Sea Turtle Designated Critical Habitat ............................................. 58

3. MAGNUSON-STEVENS FISHERY CONSERVATION AND MANAGEMENT ACT ...... 58

3.1 Essential Fish Habitat Affected by the Project ................................................................... 58

3.2 Adverse Effects on Essential Fish Habitat .......................................................................... 60

3.3 Essential Fish Habitat Conservation Recommendations .................................................... 61

3.4 Statutory Response Requirement ........................................................................................ 61

3.5 Supplemental Consultation ................................................................................................. 62

4. DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW .... 62

5. LITERATURE CITED ............................................................................................................. 64
-iiLIST OF ACRONYMS 

BA Biological Assessment 

BRT Biological Recovery Team 

CFR Code of Federal Regulations 

Corps U.S. Army Corps of Engineers 

DPS Distinct Population Segment 

DQA Data Quality Act 

EFH Essential Fish Habitat 

EPA U.S. Environmental Protection Agency 

ESA Endangered Species Act 

ESU Evolutionarily Significant Unit 

FR Federal Register 

GLOBEC Global Ocean Ecosystem Dynamics 

HAPC Habitat Area of Particular Concern 

ITS Incidental Take Statement 

LAA Likely to Adversely Affect 

LCR Lower Columbia River 

MPRSA Marine Protection, Research and Sanctuaries Act 

MSA Magnuson-Stevens Fishery and Conservation Management Act 

NLAA Not Likely to Adversely Affect 

NMFS National Marine Fisheries Service 

OC Oregon Coast 

TRT Technical Recovery Team 

ODMD Ocean Disposal Material Dredged 

PAH Polycyclic Aromatic Hydrocarbons 

PCB Polychlorinated biphenyls 

PCE Primary Constituent Elements 

PFMC Pacific Fishery Marine Council 

SEF Sediment Evaluation Framework 

SL Screening Level 

SMMP Site Management and Monitoring Plan 

SONCC Southern Oregon/Northern California Coast 

SR Snake River 

SVOC Semi-volatile Organic Compounds 

TBT Organotins 

TOC Total Organic Carbon 

TSS Total Suspended Solids 

UCR Upper Columbia River 

UWR Upper Willamette River 

VSP Viable Salmonid Population 
-1- 

1. INTRODUCTION 

This Introduction section provides information relevant to the other sections of this document 

and is incorporated by reference into Sections 2 and 3 below. 

1.1 Background

The biological opinion (opinion) portion of this document was prepared by the National Marine 

Fisheries Service (NMFS) in accordance with section 7(b) of the Endangered Species Act (ESA) 

of 1973, as amended (16 U.S.C. 1531, et seq.), and implementing regulations at 50 CFR 402. 

The NMFS also completed an essential fish habitat (EFH) consultation. It was prepared in 

accordance with section 305(b)(2) of the Magnuson-Stevens Fishery Conservation and 

Management Act (MSA) (16 U.S.C. 1801, et seq.) and implementing regulations at 50 CFR 600. 

The opinion and EFH conservation recommendations are both in compliance with section 515 of 

the Treasury and General Government Appropriations Act of 2001 (Public Law 106-5444) 

(“Data Quality Act”) and underwent pre-dissemination review. 

1.2 Consultation History 

The NMFS received a letter and a biological assessment (BA) on December 22, 2011, from the 

U.S. Environmental Protection Agency Region 10 (EPA) requesting formal consultation and 

informal consultation for ESA-listed species and critical habitats that may be affected by the 

EPA’s proposed designation of two dredged material disposal sites in the Pacific Ocean 

northwest and southwest of the mouth of the Yaquina River. The EPA determined the proposed 

action was likely to adversely affect Oregon Coast (OC) coho salmon (Oncorhynchus kisutch). 

Additionally, EPA determined that the proposed action may affect, but was not likely to 

adversely affect (NLAA) the following species: (1) Lower Columbia River (LCR) Chinook 

salmon (O. tshawytscha); (2) Upper Willamette River (UWR) Chinook salmon (O. tshawytscha); 

(3) Snake River (SR) spring/summer run Chinook salmon (O. tshawytscha); (4) southern distinct 

population segment (DPS) North American green sturgeon (hereafter referred to ‘green 

sturgeon’) (Acipenser medirostris); (5) southern DPS Pacific eulachon (hereafter referred to as 

‘eulachon’) (Thaleichthys pacificus); (6) Southern Resident killer whales (Orcinus orca); 

(7) eastern DPS Steller sea lions (Eumotopias jubatus); (8) blue whales (Balaenoptera 

musculus); (9) fin whales (B. physalus); (10) humpback whales (Megaptera novaengliae); 

(11) sei whales (B. borealis); (12) sperm whales (Physeter macrocephalus); (13) leatherback sea 

turtles (Dermochelys coriacea); (14) loggerhead sea turtles (Caretta caretta); (15) green sea 

turtles (Chelonia mydas); and (16) olive ridley sea turtles (Lepidochelys olivacea). The EPA also 

determined that the proposed action is NLAA designated critical habitat for leatherback sea 

turtles and designated critical habitat for green sturgeon. 

After reviewing information provided by the EPA, NMFS has determined that SR fall-run and 

Upper Columbia River (UCR) Chinook salmon (O. tshawytscha) also potentially occur in the 
-2- 

action area and may be affected by the proposed action. Therefore, NMFS will include these 

species in this opinion. 

The EPA included an EFH assessment in the consultation request package and determined that 

the effects of the proposed action may adversely affect EFH designated for Pacific Coast 

groundfish, coastal pelagic species, and Pacific salmon. A complete record of this consultation is 

on file at the Oregon Coast Branch of the Oregon State Habitat Office in Roseburg, Oregon. 

1.3 Proposed Action

“Action” means all activities or programs of any kind authorized, funded, or carried out, in 

whole or in part, by Federal agencies. Interrelated actions are those that are part of a larger action 

and depend on the larger action for their justification. Interdependent actions are those that have 

no independent utility apart from the action under consideration. 

The proposed action is the EPA’s designation of the Yaquina River north and south Ocean 

Disposal Material Dredged (ODMD) sites under section 102(c) of the Marine Protection, 

Research and Sanctuaries Act, as amended (MPRSA), 33 U.S.C. §§ 1401 to 1445. The proposed 

north site is located 1.7 nautical miles northwest of Yaquina Bay and the south site is about 2 

nautical miles southwest of the bay. Both ODMD sites are 4,000 feet wide by 6,500 feet long, 

about 597 acres each, and their depths range from 112 to 152 feet. Included in this designation is 

the adoption of a Site Management and Monitoring Plan (SMMP). Prior to the proposed 

designation, three sites, the interim, adjusted, and drop zone of the north site (authorized for use 

under section 103 of MPRSA in 2001), were used for disposal of dredged material (Figure 1). 

The interim and adjusted sites were determined inadequate to continue to receive disposed 

material. Use of the north site expired at the end of the 2011 dredge season and is unavailable for 

future dredge seasons unless designated as proposed in the EPA’s current designation action 

(EPA 2011). 

The SMMP has been prepared jointly by EPA, and the U.S. Army Corps of Engineers (Corps) 

(Portland District), and describes management and monitoring requirements for EPA-designated 

ODMD sites located offshore from Yaquina Bay, Oregon. This SMMP supersedes all previous 

SMMPs for the Yaquina River ODMD sites. Periodic review and updating of the SMMP will 

occur on a minimum 10-year schedule. All permits or other authorizations to use the Yaquina 

River ODMD sites shall be conditioned as necessary to assure consistency with this SMMP. 

MPRSA 102(c)(3)(E) requires that the management plan include consideration of the anticipated 

use of the site. Disposal activities associated with dredging are not conducted by the EPA, are 

subject to subsequent consultation, and are therefore not part of the EPA’s proposed action. 

However, disposal would not be able to occur but for EPA’s designation of this disposal site, so 

it constitutes an interrelated action that must be analyzed along with the proposed action. The 

EPA expects the Corps will be the primary and regular user of the Yaquina River ODMD sites 

proposed for designation for disposal of dredged material removed from the Federal navigation 

project. A summary of the Yaquina River Federal navigation project is included in the SMMP. 

Recent (last ten years) volumes of dredged material disposed of at the north ODMD site have 

averaged 217,379 cubic yards (cy) with a range from 320,455 cy in 2003 to 161,678 cy in 2009. 
-3- 

Only material from Corps Federal projects has been disposed of in the ocean, except when Port 

of Toledo disposed of 3,000 cy in 2010. The EPA expects the ODMD sites will be used in the 

future for disposal of material dredged by other public or private entities (e.g. the U.S. Coast 

Guard, Port of Newport, Port of Toledo) in accordance with Section 103 of the MPRSA. 

Disposal Capacity: Based on sediment FATE modeling, EPA expects each proposed ODMD site 

to have the capacity to receive approximately, on average, 310,000 cy of dredged material 

annually for 20 years (or 6.2 million cubic yards (mcy) each) without impacting the present wave 

climate1

. 

The type of dredge used to gather the material to be disposed influences the dimensions of the 

individual and cumulative dump mounds at the disposal sites. No specific disposal technique is 

required at the Yaquina River ODMD sites. For the hopper dredges that commonly work in the 

Yaquina River, such as the Corps’ multiple bottom door hopper dredge Yaquina, each load 

would produce a thinner deposit than the split hull contract hopper dredges typically used by 

private entities at any given water depth. Material discharged from a split-hull barge is typically 

more consolidated than material discharged from a multiple bottom-door hopper dredge. Only 

hopper dredges can be used at the Yaquina River entrance channel dredging site due to waves 

and currents. Clamshell dredges with barges can be used at estuary dredging sites such as South 

Beach Marina and Yaquina River (including Depot Slough). 

 

1

 The long-term statistical characterization of the behavior of waves in the ocean. 
-4- 

Figure 1. The EPA’s proposed Yaquina Bay north and south ODMD site locations. 
-5- 

The EPA and the Corps will closely monitor and document disposal volumes and placement, to 

verify uniform placement, and to assess dispersive capability of disposed material (EPA and 

Corps 2011a). Adverse sea and weather conditions limit dredging and disposal to a period 

typically from June 1 to October 31. Even during the dredging season, storm events can restrict 

disposal events. Environmental restrictions may be imposed on disposal. In the event that new 

information or monitoring results reveal the need for any additional restrictions, disposal 

activities will be scheduled to avoid unacceptable adverse effects (EPA and Corps 2011a). The 

EPA identified that ocean disposal in the proposed sites would occur for 6 days in April or May 

and then from June 15 to October 31. The EPA also identified three dredging sites of Yaquina 

Bay that would likely contribute to the amount of dredged material disposed at the EPA’s 

proposed ODMD sites and they include the Yaquina River entrance channel, South Beach 

Marina, and the Yaquina River (including Depot Slough) (EPA and Corps 2011b). Thirty-two 

days of dredging were identified for the Yaquina Bay entrance channel and 30 days for the 

marina and Yaquina River.2

 The total volume of dredged material estimated to be placed within 

Yaquina ODMD sites for the next 20 years was 6.2 million cubic yards (or 310,000 cy/yr). The 

maximum volumes that the Corps would dredge and dispose of from the entrance channel, South 

Beach Marina, and the Yaquina River (including Depot Slough) are 370,000 cy, 25,000 cy, and 

100,000 cy, respectively. The NMFS will use these as the proposed maximum volumes (EPA 

and Corps 2011b) when conducting our effects analysis. Dredging would occur annually for the 

entrance channel and South Beach Marina and Yaquina River are dredged every 5 to 8 years. 

The proposed maximum volume of 495,000 cy of disposed dredged material is the proposed 

amount that the EPA expects could occur in any one year.2

 The number of disposal trips per year 

will vary depending on the volume of material and disposal tactic. Based on the average volume 

of dredged material disposed of by the Yaquina hopper dredge (800 cy), the maximum number 

of disposal events that could occur when 495,000 cy of material is dredged is 619. For this 

proposed action and analysis, the EPA estimated the maximum volume (495,000 cy) of disposed 

material and number of disposal events (619) in any one year, which would include the Corps’ 

anticipated disposal activities associated with the Federal navigation project and all other entities 

(Corps, U.S. Coast Guard, private users, etc.) that may dispose at the proposed ODMD sites.3

Operation of the sites. The EPA and Corps’ environmental assessment (EPA and Corps 

2011b) described the sizing of the proposed Yaquina Bay north and south ODMD sites. The 

proposed north and south sites have been sized to provide sufficient capacity to accommodate 

material dredged from the Yaquina Federal navigation project, as well as material from other 

projects. The size of the north and south ODMD sites was modeled based on the requirement to 

provide at least 20 years of disposal capacity per site, without the sites accumulating dredged 

material to a height that could potentially amplify waves. Management of material placement 

resulting from monitoring as described in the SMMP will assure that the wave climate will not 

be significantly affected and navigational safety not compromised. 

 

2

 Number of days identified in NMFS biological opinion issued to the Corps on May 28, 2010 for the Corps 

Maintenance Dredging Program for the Oregon Coastal Projects (NMFS No.: 2009/01756). 

3

 E-mail from Bridgette Lohrman (EPA) to Jeff Young (NMFS) reporting on the EPA’s proposed maximum volume 

of disposed material per year and the number of disposal events per year associated with that volume (February 16, 

2012). 
-6- 

The Yaquina Bay north and south ODMD sites will operate under a uniform placement strategy. 

Uniform placement means the spreading of disposal activities within the sites, rather than spot 

dumping. Uniform placement at each site is expected to result in relatively uniform dispersal and 

accumulation of dredged materials on the ocean bottom. To achieve uniform placement and site 

management objectives described in the SMMP, ODMD site management will include 

establishing cells in each site to ensure uniform placement, minimize the accumulation of 

material and avoid excessive or persistent mounding. This will be established using an ODMD 

site disposal placement grid. This placement grid consists of 32 cells that are 700 feet by 700 feet 

and establish the release point for each load of dredged material. Dump plans will be developed 

and may be adjusted during each disposal season to utilize different portions or cells within the 

sites to achieve uniform placement and minimize mounding (EPA and Corps 2011b – Appendix 

B). There will be a preference for use of the north ODMD site if capacity exists. At some time, 

disposal may be alternated, as necessary, between the two sites to allow for maximum usage and 

minimal impact. The north site is anticipated to receive more frequent initial use, but this may 

change as conditions warrant. The proposed action specifies there will be a preference for 

disposal at the north ODMD site, but both ODMD sites could be used in a single dredging 

season.4

The NMFS relied on the foregoing description of the proposed action, including all stated impact 

reduction measures, to complete this consultation. To ensure that this consultation remains valid, 

NMFS requests that the action agency or applicant keep NMFS informed of any changes to the 

proposed action. 

1.4 Action Area 

“Action area” means all areas to be affected directly or indirectly by the Federal action and not 

merely the immediate area involved in the action (50 CFR 402.02). 

The EPA’s proposed north and south ODMD sites for designation are located approximately 1.7 

and 2.0 nautical miles northwest and southwest of Yaquina Bay’s entrance (Figure 1). The 

proposed Yaquina ODMD sites have the following corner coordinates (North American Datum 

[NAD] 1983). 

Proposed North Yaquina ODMD Site Proposed South Yaquina ODMD Site 

44° 38‘ 17.98 N, 124° 07‘ 25.95 W 44° 36‘ 04.50 N, 124° 07‘ 52.66 W 

44° 38‘ 12.86 N, 124° 06‘ 31.10 W 44° 35‘ 59.39 N, 124° 06‘ 57.84 W 

44° 37‘ 14.33 N, 124° 07‘ 37.57 W 44° 35‘ 00.85 N, 124° 08‘ 04.27 W 

44° 37‘ 09.22 N, 124° 06‘ 42.73 W 44° 34‘ 55.75 N, 124° 07‘ 09.47 W 

Dimensions: 4,000 feet wide Dimensions: 4,000 feet wide 

 6,500 feet long 6,500 feet long 

Depth Range: 112 to 152 feet Depth Range: 112 to 152 feet 

 

4

 E-mail from Bridgette Lohrman, EPA, to Jeff Young, NMFS (reporting on the potential use of both proposed 

disposal sites in any one dredging season) (April 5, 2012). 
-7- 

Each of the proposed ODMD sites occupies 597 acres. The action area includes both ODMD 

sites and the rectangular area within the corner coordinates, the extent of sediment drift, and the 

water column from the water surface to the ocean floor. The EPA included a 500-foot buffer 

within the sites, in which disposal will not occur in order to keep disposed material inside the 

designated area. However, long-term modeling of sediment disposal showed the sediment mound 

extending outside of the site boundaries (EPA and Corps 2011d). Thus, NMFS includes an 

additional 500 feet around the site boundaries to account for sediment dispersion outside EPA’s 

proposed boundaries. The total action area as described by NMFS is approximately 1,722 acres 

located outside the mouth of the Yaquina River at the two sites (Figure 1). Disposal of material 

at the proposed north and south ODMD sites is an indirect effect of site designation and the most 

likely aquatic impacts of disposal (suspended sediments, physical disturbance, and benthic 

effects) would be limited to this action area. 

Based on information provided by the EPA and developed during consultation, NMFS 

determined that the proposed action is likely to adversely affect (LAA) OC coho salmon, green 

sturgeon, and eulachon and is NLAA all other species that may occur in the action area (Table 

1). The NMFS also determined that the proposed action is NLAA critical habitat designated for 

green sturgeon and leatherback sea turtles (Dermochelys coriacea). Critical habitat has not been 

designated or proposed for any other species within the action area. 
-8- 

Table 1. Federal Register notices for final rules that list threatened and endangered species, 

designate critical habitats, or apply protective regulations to listed species 

considered in this consultation. Listing status: “T” means listed as threatened 

under the ESA; “E” means listed as endangered; “P” means proposed. 

Species Listing Status Critical Habitat Protective Regulations

Marine and Anadromous Fish 

Chinook salmon (Oncorhynchus tshawytscha) 

 Lower Columbia River T 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160 

 Upper Willamette River T 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160 

 Upper Columbia River spring-run E 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 ESA section 9 applies 

 Snake River spring/summer run T 6/28/2005; 70 FR 37160 10/25/99; 64 FR 57399 6/28/05; 70 FR 37160 

 Snake River fall-run T 6/28/2005; 70 FR 37160 12/28/93; 58 FR 68543 6/28/05; 70 FR 37160 

Coho salmon (O. kisutch)

 Oregon Coast 6/20/2011; 76 FR 35755 2/11/08; 73 FR 7816 2/11/08; 73 FR 7816 

 S. Oregon / N. California Coasts T 6/28/2005; 70 FR 37160 5/5/99; 64 FR 24049 6/28/05; 70 FR 37160 

Southern DPS green sturgeon (Acipenser 

medirostris) T 4/07/2006; 71 FR 17757 10/09/09; 74 FR 52300 6/02/10; 75 FR 30714 

Southern DPS eulachon (Thaleichthys 

pacificus) T 3/18/2010; 75 FR 13012 P 01/05/11; 76 FR 515 Not applicable 

Marine Mammals 

Eastern DPS Steller sea lion (Eumetopias 

jubatus) T 5/5/1997; 63 FR 24345 8/ 27/93; 58 FR 45269 11/26/90; 55 FR 49204 

Blue Whale (Balaenoptera musculus) E 12/02/1970; 35 FR 18319 Not applicable ESA section 9 applies 

Fin whale (Balaenoptera physalus) E 12/02/1970; 35 FR 18319 Not applicable ESA section 9 applies 

Humpback whale (Megaptera 

novaeangliae) E 12/02/1970; 35 FR 18319 Not applicable ESA section 9 applies 

Southern Resident killer whale (Orcinus 

orca) E 11/18/2005; 70 FR 69903 11/29/06; 71 FR 69054 ESA section 9 applies 

Sei whale (Balaenoptera borealis) E 12/02/1970; 35 FR 18319 Not applicable ESA section 9 applies 

Sperm whale (Physeter macrocephalus) E 12/02/1970 Not applicable ESA section 9 applies 

Marine Turtles 

Green turtle (Chelonia mydas) ET 7/28/1978 43 FR 32800 9/02/1998; 63 FR 46693 ESA section 9 applies 

Leatherback turtle (Dermochelys coriacea) E 6/02/70 ; 39 FR 19320 

3/23/79; 44 FR 17710 

1/26/2012 77 FR 4170 ESA section 9 applies 

Loggerhead turtle (Caretta caretta) T 7/28/78; 43 FR 32800 Not applicable 07/28/1978; 32800 

Olive ridley turtle (Lepidochelys olivacae) ET 7/28/78; 43 FR 32800 Not applicable ESA section 9 applies 
-9- 

2. ENDANGERED SPECIES ACT BIOLOGICAL OPINION AND INCIDENTAL TAKE 

STATEMENT 

The ESA establishes a national program for conserving threatened and endangered species of 

fish, wildlife, plants, and the habitat on which they depend. Section 7(a)(2) of the ESA requires 

Federal agencies to consult with the U.S. Fish and Wildlife Service, NMFS, or both, to ensure 

that their actions are not likely to jeopardize the continued existence of endangered or threatened 

species or adversely modify or destroy their designated critical habitat. Section 7(b)(3) requires 

that at the conclusion of consultation, the Service provide an opinion stating how the agencies’ 

actions will affect listed species or their critical habitat. If incidental take is expected, Section 

7(b)(4) requires the provision of an incidental take statement (ITS) specifying the impact of any 

incidental taking, and including reasonable and prudent measures to minimize such impacts. 

2.1 Introduction to the Biological Opinion

Section 7(a)(2) of the ESA requires Federal agencies, in consultation with NMFS, to insure that 

their actions are not likely to jeopardize the continued existence of endangered or threatened 

species, or adversely modify or destroy their designated critical habitat. The jeopardy analysis 

considers both survival and recovery of the species. The adverse modification analysis considers 

the impacts to the conservation value of the designated critical habitat.

“To jeopardize the continued existence of a listed species” means to engage in an action that 

would be expected, directly or indirectly, to reduce appreciably the likelihood of both the 

survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or 

distribution of that species (50 CFR 402.02). 

This opinion does not rely on the regulatory definition of “destruction or adverse modification” 

of critical habitat at 50 CFR 402.02. Instead, we have relied upon the statutory provisions of the 

ESA to complete the following analysis with respect to critical habitat.5

We will use the following approach to determine whether the proposed action described in 

Section 1.3 is likely to jeopardize listed species or destroy or adversely modify critical habitat: 

 Identify the rangewide status of the species and critical habitat likely to be adversely 

affected by the proposed action. This section describes the current status of each listed 

species and its critical habitat relative to the conditions needed for recovery. For listed 

salmon and steelhead, NMFS has developed specific guidance for analyzing the status of 

the listed species’ component populations in a “viable salmonid populations” paper 

(VSP; McElhany et al. 2000). The VSP approach considers the abundance, productivity, 

spatial structure, and diversity of each population as part of the overall review of a 

species’ status. For listed salmon and steelhead, the VSP criteria therefore encompass the 

species’ “reproduction, numbers, or distribution” (50 CFR 402.02). In describing the 

range-wide status of listed species, we rely on viability assessments and criteria in 

 

5

 Memorandum from William T. Hogarth to Regional Administrators, Office of Protected Resources, NMFS 

(Application of the “Destruction or Adverse Modification” Standard Under Section 7(a)(2) of the Endangered 

Species Act) (November 7, 2005). 
-10- 

technical recovery team documents and recovery plans, where available, that describe 

how VSP criteria are applied to specific populations, major population groups, and 

species. We determine the rangewide status of critical habitat by examining the condition 

of its physical or biological features (also called “primary constituent elements” or PCEs 

in some designations) – which were identified when the critical habitat was designated. 

Species and critical habitat status are discussed in Section 2.2. 

 Describe the environmental baseline for the proposed action. The environmental baseline 

includes the past and present impacts of Federal, state, or private actions and other human 

activities in the action area. It includes the anticipated impacts of proposed Federal 

projects that have already undergone formal or early section 7 consultation and the 

impacts of state or private actions that are contemporaneous with the consultation in 

process. The environmental baseline is discussed in Section 2.3 of this opinion. 

 Analyze the effects of the proposed actions. In this step, NMFS considers how the 

proposed action would affect the species’ reproduction, numbers, and distribution or, in 

the case of salmon and steelhead, their VSP characteristics. NMFS also evaluates the 

proposed action’s effects on critical habitat features. The effects of the action are 

described in Section 2.4 of this opinion. 

 Describe any cumulative effects. Cumulative effects, as defined in NMFS’ implementing 

regulations (50 CFR 402.02), are the effects of future state or private activities, not 

involving Federal activities, that are reasonably certain to occur within the action area. 

Future Federal actions that are unrelated to the proposed action are not considered 

because they require separate section 7 consultation. Cumulative effects are considered in 

Section 2.5 of this opinion. 

 Integrate and synthesize the above factors to assess the risk that the proposed action 

poses to species and critical habitat. In this step, NMFS adds the effects of the action 

(Section 2.4) to the environmental baseline (Section 2.3) and the cumulative effects 

(Section 2.5) to assess whether the action could reasonably be expected to: (1) 

appreciably reduce the likelihood of both survival and recovery of the species in the wild 

by reducing its numbers, reproduction, or distribution; or (2) reduce the value of 

designated or proposed critical habitat for the conservation of the species. These 

assessments are made in full consideration of the status of the species and critical habitat 

(Section 2.2). Integration and synthesis occurs in Section 2.6 of this opinion. 

 Reach jeopardy and adverse modification conclusions. Conclusions regarding jeopardy 

and the destruction or adverse modification of critical habitat are presented in Section 

2.7. These conclusions flow from the logic and rationale presented in the Integration and 

Synthesis section (2.6). 

 If necessary, define a reasonable and prudent alternative to the proposed action. If, in 

completing the last step in the analysis, NMFS determines that the action under 

consultation is likely to jeopardize the continued existence of listed species or destroy or 

adversely modify designated critical habitat, NMFS must identify a reasonable and 
-11- 

prudent alternative (RPA) to the action. The RPA must not be likely to jeopardize the 

continued existence of ESA-listed species nor adversely modify their designated critical 

habitat and it must meet other regulatory requirements. 

In this opinion, NMFS concludes that the proposed action is NLAA the following ESA-listed 

species: 

1. Lower Columbia River (LCR) Chinook salmon 

2. Upper Columbia River (UCR) Chinook salmon 

3. Upper Willamette River (UWR) Chinook salmon 

4. Snake River (SR) spring/summer Chinook salmon 

5. SR fall Chinook salmon 

6. LCR coho salmon 

7. Southern Oregon Northern California Coasts (SONCC) coho salmon 

8. Eastern DPS Steller sea lions 

9. Blue whales 

10. Fin whales 

11. Humpback whales 

12. Southern Resident killer whales 

13. Sei whales 

14. Sperm whales 

15. Green turtles 

16. Leatherback turtles 

17. Loggerhead turtles 

18. Olive ridley sea turtles 

The NMFS also concludes that the proposed action is NLAA green sturgeon and leatherback 

turtle designated critical habitat. See Section 2.11 for discussion of NLAA determinations. 

2.2 Rangewide Status of the Species and Critical Habitat 

The summaries that follow describe the status of the ESA-listed species, and their designated 

critical habitats, that occur within the geographic area of this proposed action and are considered 

in this opinion. More detailed information on the status and trends of these listed resources, and 

their biology and ecology, can be found in the listing regulations and critical habitat designations 

published in the Federal Register (Table 1, above). 

Climate change is likely to play an increasingly important role in determining the abundance of 

ESA-listed species, and the quality and function of designated critical habitats, in the Pacific 

Northwest. These changes will not be spatially homogeneous across the Pacific Northwest. Areas 

with elevations high enough to maintain temperatures well below freezing for most of the winter 

and early spring would be less affected. Low-lying areas that historically have received scant 

precipitation contribute little to total streamflow and are likely to be more affected. 

During the last century, average regional air temperatures increased by 1.5°F, and increased up 

to 4°F in some areas (USGCRP 2009). Warming is likely to continue during the next century as 
-12- 

average temperatures increase another 3°F to 10°F (USGCRP 2009). Overall, about one-third of 

the current cold-water fish habitat in the Pacific Northwest is likely to exceed key water 

temperature thresholds by the end of this century (USGCRP 2009). 

Precipitation trends during the next century are less certain than for temperature but more 

precipitation is likely to occur during October through March and less during summer months, 

and more of the winter precipitation is likely to fall as rain rather than snow (ISAB 2007, 

USGCRP 2009). Where snow occurs, a warmer climate will cause earlier runoff so stream flows 

in late spring, summer, and fall will be lower and water temperatures will be warmer (ISAB 

2007, USGCRP 2009). 

Higher winter stream flows increase the risk that winter floods in sensitive watersheds will 

damage spawning redds and wash away incubating eggs (USGCRP 2009). Earlier peak stream 

flows will also flush some young salmon and steelhead from rivers to estuaries before they are 

physically mature, increasing stress and the risk of predation (USGCRP 2009). Lower stream 

flows and warmer water temperatures during summer will degrade summer rearing conditions, in 

part by increasing the prevalence and virulence of fish diseases and parasites (USGCRP 2009). 

Other adverse effects are likely to include altered migration patterns, accelerated embryo 

development, premature emergence of fry, variation in quality and quantity of tributary rearing 

habitat, and increased competition and predation risk from warm-water, non-native species 

(ISAB 2007). 

The earth’s oceans are also warming, with considerable interannual and inter-decadal variability 

superimposed on the longer-term trend (Bindoff et al. 2007). Historically, warm periods in the 

coastal Pacific Ocean have coincided with relatively low abundances of salmon and steelhead, 

while cooler ocean periods have coincided with relatively high abundances (Scheuerell and 

Williams 2005, Zabel et al. 2006, USGCRP 2009). Ocean conditions adverse to salmon and 

steelhead may be more likely under a warming climate (Zabel et al. 2006). 

2.2.1 Status of the Species 

Climate change, as described in Section 2.2, is likely to adversely affect the size and distribution 

of populations of ESA-listed anadromous fish in the Pacific Northwest. The size and distribution 

of the populations considered in this opinion generally have declined over the past few decades 

due to natural phenomena and human activity, including the operation of hydropower systems, 

over-harvest, hatcheries, and habitat degradation. Enlarged populations of terns, seals, sea lions, 

and other aquatic predators in the Pacific Northwest have been identified as factors that may be 

limiting the productivity of some Pacific salmon and steelhead populations (Ford 2011). 

 2.2.1.1 Oregon Coast Recovery Domain 

The OC recovery domain includes OC coho salmon, green sturgeon, and eulachon, covering 

Oregon coastal streams south of the Columbia River and north of Cape Blanco. Streams and 

rivers in this area drain west into the Pacific Ocean, and vary in length from less than a mile to 

more than 210 miles in length. 
-13- 

OC coho salmon. This species includes population of OC coho salmon in Oregon coastal 

streams south of the Columbia River and north of Cape Blanco. The Cow Creek hatchery stock 

(South Umpqua population) is managed as an integrated program and is included as part of the 

evolutionarily significant unit (ESU) because the original brood stock was founded from the 

local natural origin population and natural origin coho salmon have been incorporated into the 

brood stock on a regular basis. OC coho salmon were first listed in February 2008. As part of a 

legal settlement agreement in 2008, NMFS completed a new status review for the ESU. In 2011, 

NMFS issued a final rule re-promulgating the threatened listing for OC coho salmon (USDC 

2011). 

The OC-technical recovery team (TRT) identified 56 populations; 21 independent and 35 

dependent. The dependent populations were dependent on strays from other populations to 

maintain them over long periods. The TRT also identified 5 biogeographic stratum (Table 2) 

(Lawson et al. 2007). Independent populations are populations that historically would have had a 

high likelihood of persisting in isolation from neighboring populations for 100 years and are 

rated as functionally independent and potentially independent. Dependent populations 

historically would not have had a high likelihood of persisting in isolation for 100 years. These 

populations relied upon periodic immigration from other populations to maintain their 

abundance. 

 
-14- 

Table 2. OC coho salmon populations. Dependent populations (D); functionally 

independent (FI); and potentially independent (PI) (McElhany et al. 2000, 

Lawson et al. 2007). 

Stratum Population Type Stratum Population Type 

North 

Coast 

Necanicum PI 

Mid-Coast 

(cont.) 

Alsea FI 

Ecola D Big (Alsea) D 

Arch Cape D Vingie D 

Short Sands D Yachats D 

Nehalem FI Cummins D 

Spring D Bob D 

Watseco D Tenmile D 

Tillamook FI Rock D 

Netarts D Big (Siuslaw) D 

Rover D China D 

Sand D Cape D 

Nestucca FI Berry D 

Neskowin D Sutton D 

Mid-Coast 

Salmon PI Siuslaw FI 

Devils D Lakes Siltcoos PI 

Siletz FI Tahkenitch PI 

Schoolhouse D Tenmile PI 

Fogarty D 

Umpqua 

Lower Umpqua FI 

Depoe D Middle Umpqua FI 

Rocky D North Umpqua FI 

Spencer D South Umpqua FI 

Wade D 

Mid-South 

Coast 

Threemile D 

Coal D Coos FI 

Moolack D Coquille FI 

Big (Yaquina) D Johnson D 

Yaquina FI Twomile D 

Theil D Floras PI 

Beaver PI Sixes PI 

Wainwright et al. (2008) determined that the weakest stratum of OC coho salmon were in the 

North Coast and Mid-Coast of Oregon, which had only “low” certainty of being persistent. The 

strongest stratum was the Lakes and Mid-South Coast, which had “high” certainty of being 

persistent. To increase certainty that the ESU as a whole is persistent, they recommended that 

restoration work should focus on those populations with low persistence, particularly those in the 

North Coast, Mid-Coast, and Umpqua stratum. 

A 2010 biological recovery team (BRT) (Stout et al. 2011) noted significant improvements in 

hatchery and harvest practices have been made. However, harvest and hatchery reductions have 

changed the population dynamics of the ESU. It has not been demonstrated that productivity 

during periods of poor marine survival is now adequate to sustain the ESU. Recent increases in 

adult escapement do not provide strong evidence that the century-long downward trend has 

changed. The ability of the OC coho salmon ESU to survive another prolonged period of poor 

marine survival remains in question. 

Current concerns for spatial structure focus on the Umpqua River. Of the four populations in the 

Umpqua stratum, two, the North Umpqua and South Umpqua, were of particular concern. The 

North Umpqua is controlled by Winchester Dam and has historically been dominated by 
-15- 

hatchery fish. Hatchery influence has recently been reduced, but the natural productivity of this 

population remains to be demonstrated. The South Umpqua is a large, warm system with 

degraded habitat. Spawner distribution appears to be seriously restricted in this population, and it 

is probably the most vulnerable of any population in this ESU to increased temperatures. 

Current status of diversity shows improvement through the waning effects of hatchery fish on 

populations of OC coho salmon. In addition, recent efforts in several coastal estuaries to restore 

lost wetlands should be beneficial. However, diversity is lower than it was historically because of 

the loss of both freshwater and tidal habitat loss coupled with the restriction of diversity from 

very low returns over the past 20 years. 

The BRT concluded that there is a moderate certainty of ESU persistence over the next 100 years 

and a low-to-moderate certainty that the ESU is sustainable for the foreseeable future, assuming 

no future trends in factors affecting the ESU. The NMFS issued a final determination to retain 

the ESA listing status, effective June 20, 2011. Thus, the February 2008 critical habitat 

designation and 4(d) regulations remain in effect (USDC 2011). 

Limiting factors and threats to the OC coho salmon ESU include (Stout et al. 2011, NOAA 

Fisheries 2011): 

 Degraded freshwater habitat: Floodplain connectivity and function, channel structure and 

complexity, riparian areas and large wood supply, stream substrate, stream flow, and 

water quality have been degraded because of cumulative impacts of agriculture, forestry, 

in-stream mining, dams, road crossings, dikes, levees, etc. 

 Fish passage barriers that limit access to spawning and rearing habitats. 

 Adverse climate, altered past ocean/marine productivity, and current ocean ecosystem 

conditions have favored competitors and predators and reduced salmon survival rates in 

freshwater rivers and lakes, estuaries, and marine environments. 

Mid-Coast Stratum. The mid-coast stratum of OC coho salmon consists of Salmon, 

Siletz, Yaquina, Alsea, and Siuslaw rivers and Beaver Creek independent populations. Adult OC 

coho salmon from all mid-coast populations and juveniles from Yaquina, Alsea and Siuslaw 

rivers and Beaver Creek populations will occur in the action area with individuals from Yaquina 

and Alsea rivers and Beaver Creek populations occurring most frequently. The Siletz, Yaquina, 

Alsea, and Siuslaw rivers populations are all functionally independent populations, whereas the 

Salmon River and Beaver Creek populations are potentially independent populations. Weitkamp 

and Neely (2002) showed that adult OC coho salmon from the Salmon River hatchery were 

recovered as far south as Monterey Bay, California with the majority of recoveries occurring in 

the northern and central Oregon Coast recovery areas (including the action area outside Yaquina 

Bay). Run-timing for adult OC coho salmon is September to January with a peak in November – 

December. Juvenile OC coho salmon of the mid-coast populations outmigrate beginning in 

March until the end of June. Estimates of adult OC coho spawners returning to the mid-coast 

populations show considerable variability in the annual abundance from year to year (Figure 2). 
-16- 

Figure 2. Estimated abundance of wild adult OC coho salmon spawners by population in 

the OC mid-coast stratum 1995 to 2010 (ODFW 2011). 

The number of OC coho salmon juvenile outmigrants from the mid-coast populations has not 

been studied to provide a reliable estimate by direct sampling. However, one can estimate it by 

dividing the number of returning adults by marine survival. The Oregon Department of Fish and 

Wildlife (ODFW) (2012) estimated marine survival of OC coho salmon from sub-populations in 

the Siletz, Yaquina, and Alsea populations of OC coho salmon from 1995 to 2007. Marine 

survival rates of the overall populations are likely similar to those estimated for the relative subpopulation. Estimated marine survival averaged (from 1995 to 2007) 4.1% for Siletz (range, 

0.6% to 7.4%), 10.1% for Yaquina (range, 1.3% to 22.6%), and 4.2% for Alsea (range, 0.7% to 

9.2%) populations of OC coho salmon. The Salmon River, Beaver Creek, and Siuslaw River 

populations marine survival rates are likely similar to those of the Siletz and Alsea. Therefore, 

NMFS used the ODFW (2012) estimated marine survival values for their respective populations 

and 4.15% (average for Siuslaw and Alsea populations) for the Salmon, Beaver Creek, and 

Siuslaw populations to back-calculate and estimate the number of smolts for each population. 

The number of out migrants estimated by this back calculation for each population is shown in 

Figure 3. While this extrapolation is not optimal, NMFS considers this the best available 

information and is adequate for use in the analysis portion of this opinion. 

Estimated adult spawner abundances for the mid-coast stratum populations appear to have been 

the highest in the last four to five years with the lowest abundances occurring in the late 1990s. 

The TRT estimated potential historical abundance for adult spawners for the Salmon, Siletz, 

Yaquina, Alsea, and Siuslaw rivers and Beaver Creek populations. The potential historical 

abundance of adult spawners was 17,000; 122,000; 122,000; 163,000; 267,000; and 27,000, 

respectively (Lawson et al. 2007). The potential historical abundance of juvenile smolts in the 

Yaquina and Alsea rivers and Beaver Creek populations was 1,217,000; 1,628,000; and 265,000; 

respectively (Lawson et al. 2007). Even with the considerable variability in adult return 

0

10000

20000

30000

40000

50000

60000 Salmon Siletz Yaquina Beaver Cr. Alsea Siuslaw
-17- 

estimates from year-to-year, the abundance levels in the Umpqua populations since 1995 are low 

compared to historical abundance levels. 

Figure 3. Estimated number of OC coho salmon smolts by population from back calculation 

in the OC mid-coast stratum, 1995 to 2010. 

In 2008, the Oregon and Northern California Coasts TRT developed a biological recovery 

criteria report for the OC coho salmon ESU. The primary purpose of this report was to assess the 

progress of recovery of the OC coho salmon ESU. The biological recovery criteria developed are 

framed within the context of a Decision Support System (DSS) that is organized into two 

categories; persistence and sustainability. A persistence analysis assesses the ability of the ESU 

to persist (i.e. not go extinct) over a 100-year time frame. A sustainability analysis assesses the 

ability of the ESU to maintain its genetic legacy and long-term adaptive potential for the 

foreseeable future (Wainwright 2008). In developing the criteria, the TRT explained a system 

where a persistence or sustainability value of 1 would indicate complete confidence that the ESU 

will persist or sustain itself for the next 100 years; a value of -1 would indicate complete 

certainty of failure of a population to persist or sustain itself; and a value of 0 would indicate no 

certainty of persistence, sustainability, or extinction. The BRT (Stout et al. 2011) conducted 

updated persistence and sustainability analyses for the populations in the OC coho salmon ESU. 

Results of the BRT’s persistence and sustainability analyses in Stout et al. 2011 showed that 

persistence values in the north coast populations ranged from -1.00 in the Salmon to 0.79 in the 

Beaver Creek population. Sustainability values ranged from -1.00 in the Salmon to 0.56 in the 

Beaver Creek population (Table 3). 

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000 Salmon Siletz Yaquina Beaver Cr. Alsea Siuslaw
-18- 

Table 3. Persistence and sustainability values for the mid-coast populations identified in 

Stout et al. 2011. 

Population Population 

Persistence 

Population 

Sustainability 

Population Condition 

(Persistence)3

Population Condition 

(Sustainability)3

Salmon -1.00 -1.00 Certain failure of this 

population to persist 

Certain failure of this 

population to sustain itself 

Siletz 0.34 0.38 Moderate certainty for this 

population to persist 

Moderate certainty for this 

population to sustain itself 

Yaquina 0.47 0.54 Moderate to high certainty 

for this population to 

persist 

Moderate to high certainty 

for this population to 

sustain itself 

Beaver Cr. 0.79 0.56 High certainty for this 

population to persist 

High certainty for this 

population to sustain itself 

Alsea -0.03 0.13 Low certainty of failure of 

this population to persist 

Low certainty for this 

population to sustain itself 

Siuslaw 0.17 0.35 Low to moderate certainty 

for this population to 

persist 

Moderate certainty for this 

population to sustain itself 

The ODFW identified stream complexity and water quality as the top two limiting factors for the 

Siletz, Yaquina, Alsea, and Siuslaw populations of OC coho salmon and spawning gravel and 

stream complexity for the Beaver Creek population (ODFW 2007). 

Southern DPS green sturgeon. Green sturgeon is a widely distributed and marineoriented species found in the nearshore waters from Baja California to Canada (NMFS 2008a). 

There are two distinct population segments defined for green sturgeon – a northern DPS with 

spawning populations in the Klamath and Rogue rivers and a southern DPS that spawns in the 

Sacramento River (NMFS 2008b). The southern DPS includes all spawning populations of green 

sturgeon south of the Eel River in California, of which only the Sacramento River currently 

contains a spawning population. McLain (2006) noted that green sturgeon were first determined 

to occur in Oregon and Washington waters in the late 1950s when tagged San Pablo Bay green 

sturgeon were recovered in the Columbia River estuary (CDFG 2002). 

The green sturgeon BRT convened a status review update in November 2004 (BRT 2005). The 

majority of the BRT concluded that green sturgeon is likely to become endangered in the 

foreseeable future and only one member concluded that the southern DPS is not in danger of 

extinction or likely to become endangered in the foreseeable future. Weighing heavily on this 

decision was the fact that only one population of spawning adults (Sacramento River) remains. 

The BRT felt that the blockage of green sturgeon spawning from what were certainly historic 

spawning areas above Shasta Dam and the accompanying decrease in spawning area with the 

loss of the Feather River spawning area make green sturgeon in the southern DPS at risk of 

extinction in the foreseeable future. 

Green sturgeon estuarine/marine distribution and the seasonality of estuarine use range-wide are 

largely unknown. Green sturgeon are known to congregate in coastal waters and estuaries, 

including estuaries of non-natal rivers to feed. Information from fisheries-dependent sampling 

suggests that green sturgeon only occupy large estuaries during the summer and early fall in the 
-19- 

northwestern United States. Green sturgeon are known to enter Washington estuaries during 

summer (Moser and Lindley 2007). Commercial catches of green sturgeon peak in October in 

the Columbia River estuary, and records from other estuarine fisheries (Willapa Bay and Grays 

Harbor, Washington) support the idea that green sturgeon are only present in these estuaries from 

June until October (Moser and Lindley 2007). Conducting feeding studies on green sturgeon 

have proven difficult. In addition to various invertebrates, green sturgeon appear to be 

opportunistic foragers and feed on various fish species, such as lingcod (Dumauld et al. 2008), 

herring (Erickson and Hightower 2007), sand lace, and anchovies (97 FR 52084). Lindley et al. 

(2008) described ocean migration of green sturgeon and the months in which tagged fish passed 

hydrophone arrays (Figure 4). It is unknown which individuals tagged during their study were 

southern DPS green sturgeon. However, those captured and tagged in the California waters were 

most likely, but not definitely, southern DPS. Typically green sturgeon migrate north after 

leaving their natal spawning rivers (Israel et al. 2009), further supporting that these were likely 

from the southern DPS. Mature green sturgeon may spawn every two to four years or possibly 

even less frequently. Lindley et al. (2008) revealed green sturgeon make rapid, long-distance 

seasonal migrations along the continental shelf between central California and central British 

Columbia. During the northern migration the fish approached 0.25 body lengths per second 

(BL/s). The overall maximum migration rate observed was 36 miles per day, but there were a 

range of migrations rates observed and included some as slow as 0.3 miles per day. 
-20- 

Figure 4. From Lindley et al. (2008) – detections of pinger-tagged green sturgeon by 

hydrophone arrays along the West Coast of North America (n = total number of 

unique fish observed at each location. Bar height indicates the number of unique 

fish observed per day. 

Yaquina River/Bay. Telemetry data have confirmed the presence of green sturgeon in 

Yaquina Bay that were tagged in the Sacramento River (Figure 4) (74 FR 1954; October 9, 

2009). Emmet et al. (1991) reports that green sturgeon (of undetermined DPS) are common in 

Yaquina Bay, most likely using the bay as over-summering habitat, though to a lesser extent than 

Winchester Bay and Coos Bay. In a summary of 4 years of attempted data collection (2000 to 

2004), no green sturgeon were captured in Yaquina Bay. However, during the same period, 24 

green sturgeon were captured and tagged in the ocean just off-shore from Yaquina Bay (Farr et 

al. 2001, Farr and Rein 2002, Farr and Rein 2003, Farr and Kern 2004). Green sturgeon have not 

been observed upstream of the head of tide of the Yaquina River. According to ODFW sport 

catch data, green sturgeon were caught by recreational fisherman in Yaquina Bay and River 17 

out of the last 27 years (Table 4). Sport catches ranged from 0 to 26 in 1988. The ODFW also 
-21- 

reported 21 fish caught in 1988 and 24 in 2007. Whether sport caught green sturgeon reported by 

ODFW were from the southern or northern DPS is unknown. 

Table 4. Expanded catch of green sturgeon in the Yaquina Bay and River 1986 – 2010 

(ODFW 2008 and ODFW 2011). 

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total 

1986 0 0 0 0 0 0 0 0 0 0 0 0 0 

1987 0 0 0 0 0 0 0 0 0 0 0 0 0 

1988 0 0 0 0 0 0 0 0 0 0 0 0 26 

1989 0 0 0 0 0 0 0 0 0 0 0 0 21 

1990 0 0 0 0 0 0 0 0 0 0 0 0 3 

1991 0 0 0 0 0 0 0 0 0 0 0 0 13 

1992 0 0 0 0 0 0 0 0 0 0 0 0 16 

1993 0 0 0 0 0 0 0 0 0 0 0 0 16 

1994 0 0 0 0 0 0 0 0 0 0 0 0 0 

1995 0 0 0 0 0 0 0 0 0 0 0 0 0 

1996 0 0 0 3 0 3 0 0 0 0 0 0 6 

1997 4 4 0 7 0 4 0 0 0 0 0 0 19 

1998 4 0 0 0 0 0 0 0 0 0 0 4 8 

1999 0 0 11 0 0 0 6 0 0 0 0 0 17 

2000 4 0 0 0 0 0 0 0 0 0 0 0 4 

2001 0 0 0 0 10 3 0 0 0 0 0 0 13 

2002 0 0 0 0 0 0 0 3 0 0 0 0 3 

2003 0 0 0 0 0 0 0 3 0 0 0 0 3 

2004 0 0 0 0 0 0 0 0 0 0 0 0 0 

2005 0 0 0 4 0 0 0 0 0 0 0 0 4 

2006 0 4 0 0 0 0 0 0 0 0 0 0 4 

2007 0 0 0 0 14 5 0 5 0 0 0 0 24 

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 

2009 0 0 0 0 0 0 0 0 0 0 0 0 0 

2010 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eulachon. The southern DPS of eulachon extends from the Skeena River in British 

Columbia south to the Mad River in Northern California (inclusive). In the portion of the 

species’ range that lies south of the U.S.–Canada border, most eulachon production originates in 

the Columbia River basin. In the Columbia River basin, the major and most consistent spawning 

runs return to the mainstem of the Columbia River and the Cowlitz River. Spawning also occurs 

in the Grays, Elochoman, Kalama, Lewis, and Sandy rivers. Adult eulachon have been recorded 

at several locations on the Washington and Oregon coasts, and they were previously common in 

Oregon’s Umpqua River and the Klamath River in northern California. Runs occasionally occur 

in many other rivers and streams, although these tend to be erratic, appearing in some years but 
-22- 

not others, and appearing only rarely in some river systems (Hay and McCarter 2000, Willson et 

al. 2006, Gustafson et al. 2010). Core populations for this species include the Fraser River, 

Columbia River, and (historically) the Klamath River. 

Eulachon eggs are broadcast over and attach to a variety of substrates from sand to pea-sized 

gravel. Newly hatched young are carried to the sea with the current and widely dispersed by 

estuarine and ocean currents. After three to five years at sea, they return as adults to spawn. 

Marine migrations of eulachon are largely unknown; however, it appears that there is spatial 

structure to the distributions of fish from different rivers. Beacham et al. (2005) estimated 

proportional composition of three marine-caught samples from Nootka Sound, Chatham Sound, 

and Queen Charlotte Sound in Canada. Using deoxyribonucleic acid (DNA) analysis Beacham et 

al. (2005) determined that significant portions of the Nootka Sound and Queen Charlotte Sound 

samples consisted of eulachon from the Columbia River. This suggests that eulachon migrate 

large distances from their natal streams during the ocean residence portion of their life cycle. 

Eulachon have been observed as bycatch in the west coast pink shrimp fisheries (Barraclough 

1964) and groundfish surveys (Weinberg et al. 1994, Wilkins et al. 1998, Shaw et al. 2000, 

Weinberg et al. 2002) up and down the west coast of the U.S. and Canada. The amount of 

eulachon bycatch in these fisheries and surveys seems to indicate that the distribution of these 

organisms overlap in the ocean. Barraclough (1964) describes the depth range at which eulachon 

were caught as bycatch in mid-water trawls and pink shrimp trawls from 72 feet to 630 feet. Hay 

and McCarter (2000) showed the offshore distribution of eulachon in British Columbia as 

determined in research trawl surveys, which indicate that most eulachon were taken at around 

328 feet, although some were taken as deep as 1,640 feet and some less than 33 feet. Groundfish 

surveys (Weinberg et al. 1994, Wilkins et al. 1998, Shaw et al. 2000, Weinberg et al. 2002) 

occurred at depths of 180 feet to 600 feet along the continental shelf. In 2002, the NMFS 

Northwest Fisheries Science Center conducted trawl surveys along the west coast. During these 

surveys, eulachon were captured at two survey stations at Heceta Head and one survey station at 

Newport near the action area. The trawl in these surveys covered depths from 0 to 59 feet 

(NWFSC 2002). 

There are few direct estimates of eulachon abundance. In most areas of the southern DPS, 

escapement counts or estimates of spawning-stock biomass are unavailable. When available, 

catch statistics from commercial or recreational eulachon fisheries have been used as proxies of 

relative abundance. However, inferring population status or even trends from yearly changes in 

catch statistics requires assumptions that are seldom met including consistent fishing effort and 

efficiency, the relationship of the harvested portion to the total abundance of the stock, that catch 

represents a random sample of the entire population, etc. However, the combination of catch 

records and anecdotal information indicate that eulachon were present in large annual runs in the 

past and that significant declines in abundance have occurred over the last 20-30 years 

(Gustafson et al. 2010). Of the four components of species viability criteria, abundance of the 

eulachon has declined to historical low levels, productivity is of concern due to climate change, 

diversity is limited to a single age class, and spatial structure is declining as runs sizes dwindle 

throughout their range (Drake et al. 2008). 
-23- 

The Columbia River and its tributaries support the largest known eulachon run. Although direct 

estimates of adult spawning-stock abundance are unavailable, records of commercial fishery 

landings begin in 1888 and continue as a nearly uninterrupted data set to 2010 (Gustafson et al. 

2010). Historic commercial catch levels were typically more than 500 metric tons,6

 and 

occasionally exceeded 1,000 metric tons, from about 1915 to 1992. In 1993, the catch level 

began to decline; it averaged less than five metric tons from 2005 through 2008 (Gustafson et al. 

2010). Some of this pattern is due to fishery restrictions, which were put in place in response to 

the sharp decline in abundance. Persistent low returns and landings of eulachon in the Columbia 

River from 1993 to 2000 prompted the states of Oregon and Washington to adopt a Joint State 

Eulachon Management Plan (WDFW and ODFW 2001). All eulachon fisheries in Washington 

and Oregon were closed in 2011. Similar declines in eulachon abundance have occurred in the 

Fraser and other coastal British Columbia rivers (Hay and McCarter 2000, Moody 2008). No 

long-term monitoring program for eulachon exists in Northern California, but large spawning 

aggregations of eulachon were regularly reported in the Klamath River (Fry 1979, Moyle et al. 

1995, Larson and Belchik 1998, Moyle 2002, Hamilton et al. 2005). Although NMFS is 

reasonably confident that eulachon have declined substantially in the Klamath River, it is also 

clear that they have not been absent from this area in recent years. In particular, recent reports 

from Yurok Tribal fisheries biologists note a few eulachon being caught incidentally in other 

fisheries on the Klamath in 2007 and 2011—thus demonstrating that eulachon still enter the 

Klamath River in low numbers. Eulachon numbers are at, or near, historically low levels 

throughout the range of the southern DPS. 

There are no direct estimates of productivity for any eulachon populations within the southern 

DPS. However, the ability of the Columbia River eulachon stock to respond rapidly to the good 

ocean conditions of the late 1999–early 2002 period illustrates the species’ resiliency (Gustafson 

et al. 2010). This resiliency buffers the species against future environmental perturbations. The 

productivity potential or intrinsic rate of increase of eulachon (Musick et al. 2000), as indicated 

by life history characteristics such as low age-at-maturity, small body size, and planktonic larvae, 

likely confer some resilience to extinction risk as they retain the ability to rapidly respond to 

favorable ocean conditions (Gustafson et al. 2010). However, there are no empirical or 

theoretical grounds to conclude that a species with high fecundity is more resilient to extinction 

than a species with lower fecundity (Sadovy 2001, Reynolds et al. 2005). 

There is currently little information available about eulachon distribution and spawning in 

Yaquina Bay/River. However, the information that is available (Willson et al. 2006, Emmett et 

al. 1991, Monaco et al. 1990, Borgerson et al. 1991) appears to suggest that eulachon occur in 

Yaquina Bay on an infrequent basis and in small numbers. 

The primary limiting factors responsible for the decline of the southern DPS of eulachon are 

changes in ocean conditions due to climate change (Gustafson et al. 2010, Gustafson et al. 

2011), particularly in the southern portion of its range where ocean warming trends may be the 

most pronounced and may alter prey, spawning, and rearing success. Additional factors include 

climate-induced change to freshwater habitats, dams, and water diversions (particularly in the 

 

6

 The U.S. ton is equivalent to 2,000 pounds and the metric ton is equivalent to 2,204 pounds. 
-24- 

Columbia and Klamath Rivers where hydropower generation and flood control are major 

activities), and bycatch of eulachon in commercial fisheries (NOAA Fisheries 2011). 

Other limiting factors include (Gustafson et al. 2010, Gustafson et al. 2011): 

 adverse effects related to dams and water diversions 

 artificial fish passage barriers 

 increased water temperatures, insufficient streamflow 

 altered sediment balances 

 water pollution 

 over-harvest 

 predation 

2.2.2 Status of the Critical Habitat 

Climate change, as described in Section 2.2, is likely to adversely affect the quality and function 

of designated critical habitats in the Pacific Northwest. The condition of critical habitats 

considered in the opinion generally declined during the era of European settlement due to 

depletion of cold water habitat and other variations in quality and quantity of spawning, rearing 

and migration habitats associated with development of riverine and estuarine areas (Ford 2011). 

Green sturgeon critical habitat. For freshwater rivers north of and including the Eel 

River, the areas upstream of the head of the tide were not considered part of the geographical 

area occupied by the southern DPS. However, the critical habitat designation recognizes not only 

the importance of natal habitats, but of habitats throughout their range. Critical habitat has been 

designated in coastal U.S. marine waters within 60 fathoms depth from Monterey Bay, California 

(including Monterey Bay), north to Cape Flattery, Washington, including the Strait of Juan de 

Fuca, Washington, to its United States boundary; the Sacramento River, lower Feather River, 

and lower Yuba River in California; the Sacramento-San Joaquin Delta and Suisun, San Pablo, 

and San Francisco bays in California; the lower Columbia River estuary; and certain coastal bays 

and estuaries in California (Humboldt Bay), Oregon (Coos Bay, Winchester Bay, Yaquina Bay, 

and Nehalem Bay), and Washington (Willapa Bay and Grays Harbor) and freshwater (USDC 

2009). Table 5 below delineates PCEs for green sturgeon. 
-25- 

Table 5. PCEs of critical habitat designated for green sturgeon and corresponding species 

life history events. 

Primary Constituent Elements Species Life History Event Site Type Site Attribute 

Freshwater 

riverine system 

Food resources 

Migratory corridor 

Sediment quality 

Substrate type or size 

Water depth 

Water flow 

Water quality 

-Adult spawning 

-Embryo incubation, growth and development 

-Larval emergence, growth and development 

-Juvenile metamorphosis, growth and development 

Estuarine areas Food resources 

Migratory corridor 

Sediment quality 

Water flow 

Water depth 

Water quality 

-Juvenile growth, development, seaward migration 

-Subadult growth, development, seasonal holding, and movement 

between estuarine and marine areas 

-Adult growth, development, seasonal holding, movements 

between estuarine and marine areas, upstream spawning 

movement, and seaward post-spawning movement 

Coastal marine 

areas 

Food resources 

Migratory corridor 

Water quality 

-Subadult growth and development, movement between estuarine 

and marine areas, and migration between marine areas 

-Adult sexual maturation, growth and development, movements 

between estuarine and marine areas, migration between marine 

areas, and spawning migration 

The green sturgeon critical habitat analytical review team identified several activities that may 

threaten the PCEs in coastal bays and estuaries and may necessitate the need for special 

management considerations or protection. The application of pesticides may adversely affect 

prey resources and water quality within the bays and estuaries, as well as the growth and 

reproductive health of green sturgeon through bioaccumulation. Other activities of concern 

include those that may disturb bottom substrates, adversely affect prey resources, or degrade 

water quality through re-suspension of contaminated sediments. Of particular concern are 

activities that affect prey resources. Prey resources can be affected by: commercial shipping and 

activities generating point source pollution and non-point source pollution that can discharge 

contaminants and result in bioaccumulation of contaminants in green sturgeon; disposal of 

dredged materials that can bury prey resources; and bottom trawl fisheries that can disturb the 

bottom (but may result in beneficial or adverse effects on prey resources for green sturgeon). In 

addition, petroleum spills from commercial shipping activities and proposed alternative energy 

hydrokinetic projects may affect water quality or hinder the migration of green sturgeon along 

the coast (USDC 2009). 

Critical habitat is designated for green sturgeon that includes the action area. The PCEs consist 

of physical and biological features identified as essential to the conservation of green sturgeon in 

documents that designated critical habitat. The PCEs present in the action area consist of those 

necessary for life stages of green sturgeon that occupy coastal marine areas (Table 5) and include 

forage, safe passage, and water quality. The NMFS identified nearshore ocean habitat in the 

action area as high conservation value habitat due to the role this habitat provides for migration 

and connection between the northern estuaries and the southern spawning habitat (NMFS 

2008b). 
-26- 

2.3 Environmental Baseline

The “environmental baseline” includes the past and present impacts of all Federal, state, or 

private actions and other human activities in the action area, the anticipated impacts of all 

proposed Federal projects in the action area that have already undergone formal or early section 

7 consultation, and the impact of state or private actions which are contemporaneous with the 

consultation in process (50 CFR 402.02). 

The action area is in the Pacific Ocean offshore of the mouth of Yaquina Bay (Figure 1) and 

covers approximately 1,194 acres. There are two components of the action area, a north and 

south ODMD site. Environmental conditions were described in the BA (EPA 2011). Each of the 

proposed ODMD sites is approximately 597 acres (6,500-feet long by 4,000-feet wide). Based on 

sediment FATE modeling NMFS added 500 feet around each site for sediment dispersion 

making the affected area for each site approximately 861 acres. Ocean depths range from 112 to 

152 feet. The north and south ODMD sites are located on the continental shelf where the 

sediment cover is sand extending seaward from land for over 10 nautical miles. 

The Yaquina Bay zone of siting feasibility (ZSF) is characterized primarily by fine sand with 

exposed rock outcroppings. To the north of the Section 103 disposal site, there exists a large area 

of seabed rock exposure. These seabed rock outcroppings contribute coarser sediment to the 

nearshore area as rock surfaces are eroded by wave action. 

Ocean water circulation near the proposed north and south Yaquina ODMD sites is directly 

influenced by larger-scale regional currents and weather patterns in the northwestern Pacific 

Ocean. During winter, strong low-pressure systems with winds and waves predominantly from 

the southwest contribute to strong northward currents. During summer, high-pressure systems 

dominate and waves and winds are commonly from the north. Along the Oregon Coast, there is a 

southerly wind in summer that creates a mass transport of water offshore resulting in upwelling 

of cold, nutrient-rich bottom water nearshore. 

Disposal history. Yaquina River enters the Pacific Ocean near the city of Newport, 

Oregon, approximately 115 miles south of the Columbia River. The Corps has been responsible 

for maintenance of navigable waterways of the north Pacific coast since 1871. The need for 

improved navigation controls in the Yaquina Bay estuary began with the founding of the port 

city at Yaquina. Congress authorized dredging in the bay in 1919. 

Historic offshore disposal (pre-1977). Prior to the Interim Site receiving designation in 

1977, the Corps had historically used the same general area as the proposed ODMD sites for 

dredged material disposal since at least 1916. Approximately 200,000 cy annually were dredged 

from 1919 to 1968. The Corps records of dredging from 1959 to 1969 (excluding 1968) show 

that 247,737 cy (Table 6) was fairly typical of quantities removed (Percy et al. 1974). Interim 

site designations in 1977 were an attempt by EPA to document and establish coordinates for 

historically used Corps disposal sites. 

Offshore disposal (1977 – 2000). In January 1977, the Interim Site received its interim 

designation when EPA issued final Ocean Dumping Regulations (40 CFR 228). Between 1977 
-27- 

and 1985, material was placed in the Interim Site. Due to increased mounding at the Interim Site 

and its potential adverse effect on navigation safety, in 1986 the Corps selected an alternate 

ODMD site under its Section 103 authority, the 1986 nearshore Section 103 site (see Figure 1). 

From 1986-2000, dredged material was placed in the nearshore Section 103 site. Due to 

mounding, the nearshore Section 103 site was expanded in 1998 to include the outer two-thirds 

of the EPA Interim Site; material was placed in this expanded area in 1999. 

Offshore disposal (2001 – Present). In 2001, the Corps, under its Section 103 authority, 

selected two new ODMD sites (North Site and South Site) for the disposal of dredged material. 

The EPA concurred in a July 19, 2001 letter for the first 5-year period. The North Site was first 

used in 2001 and expired in 2006 with an option for an additional 5 years. The EPA issued a 

second Section 103 concurrence letter dated April 27, 2007 for continued use of the North Site. 

This allowed use of the North Site until the end of the 2011 dredging season. 

Between 2001 and 2009, the Corps placed all dredged material in the northern half of the Section 

103 North Site. In 2009 and 2010, material from Depot Slough was dredged by clamshell and 

barged to the North Site. Also, the Corps placed a portion of the material from the Yaquina Bay 

federal project in the southern half of the North Site. The Corps, in 2011, placed all dredged 

material in the southern half of the North site. No material has been placed in the South Site as of 

the end of the 2011 dredging season. 
-28- 

Table 6. Volume of dredged material placed at Yaquina Bay ODMD sites. 

ODMDS Location Year Total (cy) Annual Average at Site 

(cy) 

Interim Site 

1928-1940* 1,040,000 

252,379 

1941-1967* 5,400,000 

1968-1981* 6,440,000 

1982 331,180 

1983 453,319 

1984 670,773 

1985 302,764 

Interim Site Total 14,638,036 

Nearshore Section 

103 Site 

1986 242,468 

310,240 

1987 537,843 

1988 324,519 

1989 333,807 

1990 216,696 

1991 316,956 

1992 321,652 

1993 358,407 

1994 206,971 

1995 393,641 

1996 314,636 

1997 370,000 

1998 351,000 

1999 260,000 

2000 105,000 

Section 103 Site Total 4,653,596 

North ODMDS 

2001 198,284 

217,379 

2002 179,427 

2003 320,455 

2004 241,293 

2005 282,596 

2006 223,150 

2007 192,352 

2008 175,031 

2009 161,678 

2010 199,524 

North ODMDS Total 21,465,422 

*Volumes are approximate 

 Sediments. Classification of bottom sediments in the action area using high-resolution 

side-scan sonar showed that the action area bottom consists primarily of fine sand (EPA and 

Corps 2011b). There is almost a complete lack of finer silts and clays offshore of Yaquina Bay 

until silt appears at a depth of 300 feet. This lack of silt or clay is likely due to the high wave 

energy regime. Summer wave conditions produce bottom ripples to depths over 300 feet while 

winter storm waves can produce ripples to over 600 feet (Komar et al. 1972 as cited in EPA and 

Corps 2011b). 
-29- 

In June 2008, the EPA collected 18 sediment samples at the Yaquina 103 north and south sites 

for physical and chemical analysis. Samples were analyzed for grain size, total solids, total 

organic carbon (TOC), metals, organotin (TBT), semi-volatile compounds (SVOCs), 

polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Samples were 

characterized by whether or not disposal of dredged materials had previously occurred at the 

sample location. Those samples taken where disposal of dredged material from Yaquina Bay has 

occurred were from the north site drop zone and those taken where no disposal has occurred 

(background stations) were from the southern part of the north site, those within the south site, 

and those outside of the proposed ODMD sites. 

 Physical analyses. Physical analyses showed primarily medium sand with little variation. 

The percent sand was essentially the same at the north site drop zone as that of the background 

stations, (97.8% to 99.7% in the north site drop zone as compared to 96.6% to 99.5% in the 

background stations [EPA and Corps 2011c]) as was the mean percent sand at 98.6% and 98.3%, 

respectively. Mean grain sizes at the north site drop zone were more consistent than those at the 

background stations, ranging 0.195 millimeters (mm) to 0.213 mm in the north site drop zone 

and 0.171 mm to 0.308 mm in the background stations (EPA and Corps 2011c). 

 Chemical analyses. The EPA analyzed the 2008 samples for metals, TBT, SVOCs, PCBs, 

and PAHs. Metals concentrations detected in all samples were below sediment evaluation 

framework (SEF) (SEF 2009) screening limits (SLs) and were comparable between the north site 

drop zone and back ground stations. The EPA did not detect antimony, cadmium, cobalt, copper, 

mercury, selenium, and thallium at any of the sampling stations. No TBT, PCBs, or pesticides 

were detected at any sampling station. All detected concentrations of SVOCs (including PAHs) 

in the north site drop zone and background stations were below SEF SLs. Laboratory reporting 

limits for the following compounds exceeded the SEF SLs, however, none were detected above 

reporting limits in any samples: 2,4-dimethylphenol, dieldron, heptachlor, hexachlorobenzene, 

hexachlorobutadiene, and n-nitrosodiphenylamine. The sediments in the north site drop zone 

stations do not appear to have been negatively impacted by dredged material disposal (EPA 

Corps 2011c). 

Physical and chemical evaluation sampling was performed by the Corps at Yaquina Bay and 

South Beach Marina in 1980, 1986, 1990, 1991, 1995, 2000, 2005, and 2010 (these reports are 

available at http://www.nwp.usace.army.mil/environment/sediment.asp). Potential sources of 

contaminants to the Federal navigation channel are logging, wood processing, fish processing 

and urban runoff. Over the years, sediment studies have shown sediment is typically below 

screening levels for contaminants of concern. Consequently, sediment has been acceptable for inwater ocean disposal. In July of 2010, eight sediment samples were taken from Yaquina Bay as 

follows: (1) Two from the Yaquina Bay entrance channel; (2) four from the federal navigation 

(Yaquina River) channel; and (3) three from the South Beach Marina. The Corps conducted 

physical analyses on all samples. Based upon grain size and sample location, 5 out of the 9 

samples were subjected to chemical analyses. Sampling and analyses of sediments were 

conducted in accordance with the SEF (2009). 
-30- 

 Physical analyses. The overall mean grain size for the samples taken from Yaquina Bay 

was 72% sand. The mean grain size for the federal navigation channel (Yaquina River from the 

entrance channel to the turning basin) was 94% sand and 45% sand in the South Beach Marina. 

 Chemical analyses. Five of the nine samples were subjected to chemical analyses. 

Sediment samples from Yaquina Bay were analyzed for metals, TOC, pesticides, PCBs, phenols, 

phthalates, miscellaneous extractables, PAHs and TBT and all tested well below SEF SLs. Thus, 

the sediment analyzed from the 2010 samples was determined to meet the guidelines established 

in SEF (2009) for unconfined in-water placement without further characterization. 

 Water quality. The EPA (2011) reported that Water quality throughout the action area is 

typical for Oregon nearshore marine waters. Water column chemistry and physical 

characteristics offshore of the Yaquina River were studied in 1980 (Fuhrer and Rinella 1982). 

All parameters measured were well within normal ranges expected for nearshore ocean waters 

and met the state’s water quality standards. Specific information pertaining to total suspended 

solids (TSS) was not provided in the BA. Typical TSS values in waters of the West Coast shelf 

ranged from 0 to 10 milligrams per liter (mg/l) with the 50th percentile of 4.0 mg/l. These values 

represent data from the 2003 sampling of 137 stations from California, Oregon, and Washington 

collected during an ecological condition cruise (Nelson et al. 2008). 

Mounding. In general, Pacific Northwest ocean dumping sites are dispersive. However, 

mounds (and potential navigation hazards) develop when more material is placed in discrete 

locations than the ocean has capability to disperse before the next disposal event. Current 

understanding and experience indicate generally slow dispersion from mounds at ocean depths 

greater than 59 feet, with dispersion steadily decreasing with increasing depth. Much higher 

dispersion rates have been observed within nearshore areas with depths shallower than 59 feet. 

Between 2001 and 2009, all dredged material was placed in the northern half of the proposed 

north ODMD site. Maximum mound height in 2007 reached five feet, while in 2008, it reached 

six feet and in 2009, the maximum mound height reached ten feet relative to July 2001. Portions 

of the north half of the north site have mounded 10-12 feet above the 2001 baseline bathymetry. 

The southern half of the proposed north ODMD site has areas that have not changed in depth and 

some areas that have accreted up to 2 feet. This accretion can be attributed to disposal during the 

2009 dredging season and severe storms rearranging the seafloor sediments. 

Biotic community. Studies along the coast have demonstrated summer chlorophyll a (chl) 

concentration is related to winter river outflow and continental shelf widths (Chase et al. 2007). 

The winter river flows carry iron into the ocean which is later brought back into the shallows 

with the summer upwelling, thus fueling phytoplankton production. Chase et al. (2007)

presented chl concentrations from the sea-viewing-wide-field-of-sensor (SeaWiFS) satellite data

and the study area included this action area. Based on this SeaWiFS data presented in Chase et 

al. (2007), chl concentrations are likely moderately high in a narrow bandwidth along the Oregon

Coast nearshore. The action area chl concentrations from this satellite data presentation appear

comparable to other northern waters due to being in the vicinity of the Yaquina River. The

influence of the Yaquina River and the subsequent ocean upwelling that bring the iron-rich

nutrients back into the shallower water provide the basis for a rich phytoplankton community.
-31- 

Surface water chl concentrations along the West Coast shelf ranged from 0 to 28 micrograms per 

liter (μg/L). The 50th percentile of area sampled had a chl concentration of 3.9 μg/L, while the 

90th percentile had a chl concentration of 14.5 μg/L. These values represent data from the 2003 

sampling of 187 stations from California, Oregon, and Washington collected during a cruise to 

assess ecological conditions along the West Coast shelf (Nelson et al. 2008). 

Bi et al. (2008) used increasing concentrations of chl as an indicator of primary production 

coupled with decreasing water depths to classify yearling coho salmon habitat quality. In their 

2007 study (Bi et al. 2007), the foundation of their 2008 paper, they relied on low-zero catch 

probability as an indicator of habitat use; that is, they used fish sampling data and the presence or 

absence of yearling coho salmon to indicate habitat use and preferred quality. Given habitat use, 

they used step-wise regression to assess habitat condition indicators. The probability of having a 

zero-catch (of yearling coho salmon) decreased with increasing chl concentration and decreasing 

water depth. Based on the Chase et al. (2007) chl data presentation, the action area has chl 

concentrations comparable to northern Oregon and Washington waters. In general chl 

concentrations are likely lower and less widely distributed than the areas off the Washington 

coast (Bi et al. 2008). Additional environmental factors, as yet not understood, also determine 

yearling coho salmon abundance (Bi et al. 2008). 

In the 2008 paper, Bi et al. characterized yearling coho salmon habitat as favorable, potentially 

favorable, or unfavorable based on the water depth, chl, and coho salmon yearling abundance. 

Based on combining predictive habitat modeling and yearling coho salmon sampling data the 

researchers classified these habitats and presented abundance estimates. Large variability exists 

with these data and the subsequent abundance estimates. Year to year variation in predicting the 

location of these three habitat categories also varies significantly (Bi et al. 2008). It is likely the 

action area is favorable or potentially favorable habitat based on the water depth and chl 

concentrations, but the habitat quality will vary from year to year as observed with these studies. 

Some years the action area may even be unfavorable depending on upwelling. 

Keister and Peterson (2003) provided a discussion of the zooplankton community found off the 

central Oregon Coast (along the Newport hydrographic line). They indicate in their study that the 

zooplankton community is influenced strongly by seasonal variations in wind and current 

patterns. During late spring and summer, northwesterly winds set up equatorward flow and 

coastal upwelling. Northwesterly winds dominate from April/May-September where periodic 

relaxations or southwesterly storms rapidly affect the hydrography of nearshore areas. Offshore, 

about 19 miles, conditions are less variable. Boreal neritic copepods such as Pseudocalanus 

mimus, Calanus marshallae, Centropages abdominalis, Acartia longiremis, and Acartia 

hudsonica dominate the coastal plankton during summer (Peterson and Miller 1977). In early 

fall, winds reverse and upwelling ceases; during autumn and winter, winds are predominantly 

southwesterly, the Davidson Current flows poleward, and offshore surface waters are transported 

onshore. In winter, the coastal zooplankton is populated by warm-water species such as 

Mesocalanus tenuicornis, Paracalanus parvus, Ctenocalanus vanus, Clausocalanus spp., 

Acartia tonsa, and Corycaeus anglicus (Peterson and Miller 1977). The action area is within the 

continental shelf depths, so it will be assumed the area is productive yearling coho salmon and 

juvenile and adult eulachon habitat when ocean conditions are optimal. 
-32- 

The EPA (2011) provided results from field surveys conducted at or near the proposed ODMD 

sites in March 1984, May 1986, October 1989, May 1999, September 1999, June 2000, 

September 2000, June 2008, and August 2008. Dominant species and groups included 

gammaridean amphipods, sand dollars Dendraster eccentricus, surface-dwelling gastropods 

Olivella spp., and various species of polychaete worms. The benthic invertebrate fauna densities 

and diversities collected during these studies were typical of the nearshore sandy substrate along 

the Oregon coast (EPA 2011). 

The most recent data collection efforts to describe benthic infauna densities and diversities 

occurred in June and August 2008. The dominate species from the June 2008 efforts were the 

polychaetes Chaetozone nr. setosa, Magelona sacculata, Nephtys caecoides, Onuphis iridescens, 

Spio filicornis, and Spiophanes bombyx; the crustaceans Anchicolurus occidentalis and 

Eohaustorius estuarius; and the miscellaneous phylum nemertinea. The number of polychaetes, 

specifically Spiophanes bombyx at a count of 3,313, far exceeded the number of other individual 

organisms. In August 2008 the dominate species were the polychaetes Magelona sacculata, Spio 

filicornis and Spiophanes bombyx; the mollusca Siliqua sp. juvenile (razor clam); the crustacea 

Anchicolurus occidentalis, Diastylopsis dawsoni and Photis sp. indeterminate; and the 

miscellaneous phylum nemertinea. As in June, the count of Spiophanes bombyx exceeded the 

number of other individual organisms. 

To further describe the benthic infauna baseline, EPA (2011) broke the data from June and 

August 2008 into four groups based on their similarities in relative impact from disposal of 

dredged material and includes: (1) North ODMD site drop zone; (2) southern part of north 

ODMD site; (3) south ODMD site; and (4) outside proposed ODMD sites. EPA (2011) 

considered the latter three groups baseline stations because they were relatively unimpacted by 

disposal at the time these data were collected. After comparing the number of species and 

individuals between the four sites (number of species and individuals were lower in North 

ODMD site drop zone than baseline stations), EPA (2011) stated that there appears to be a 

decrease in the numbers of species and individuals in response to disposal. This difference 

indicates a potential effect from disposal of dredged material at the location. 

The EPA (2011) stated that these studies consistently found the benthic community to be 

dominated by mobile organisms that are adapted to a sandy environment. This benthic 

community provides an important link in the marine food web. These organisms serve as a direct 

food source for other benthic organisms and demersal fishes. They also play an active role in the 

breakdown of organic debris and the tube-building species help stabilize the marine sediments. 

Many of the benthic species in this study are able to survive in this dynamic environment being 

either very mobile or being able to react both to natural or anthropogenic perturbations. They 

readily recolonize in disturbed areas. 

Demersal fish and epibenthic species captured by otter trawl in the vicinity of the proposed 

Yaquina north and south ODMD sites included several commercially important species, such as 

sole, flounder, and Dungeness crab. The trawl samples denote the nearshore area as a nursery 

ground with an abundant food source. Most of the species encountered in the trawl samples were 

benthic feeders that inhabit areas where there tends to be abundant food and fewer predators. The 
-33- 

majority of the fish (75%) captured in the trawls were juveniles. However, larger fish have the 

ability to avoid the trawl net and so may have been under-represented in the species captured. 

The action area is in the nearshore area of the Pacific Ocean off the Yaquina River. The action 

area supports anadromous salmonids including OC coho salmon, winter steelhead, and springand fall-run Chinook salmon, as well as a variety of other pelagic and demersal fish species. The 

action area lies approximately 2.3 miles offshore from the mouth of the Yaquina River; therefore 

use of this area by all of these anadromous salmonid species is much more likely than most other 

areas of the Pacific Ocean. OC coho salmon marine survival in the Pacific Ocean has been 

positively correlated with the strength of coastal upwelling during the summer of smolt 

outmigration and in turn this influences primary and secondary production (Pearcy 1992). As 

previously noted, the summer upwelling provides the nutrients to fuel primary and secondary 

production that in turn determines habitat quality in the form of available yearling OC coho 

salmon forage (Bi et al. 2008, Chase et al. 2007). Based on available information regarding 

general water quality conditions, water depths, and primary and secondary production, the 

baseline conditions of the action area provide, at a minimum, sufficient conditions to support 

coho salmon. The habitat quality of these conditions varies from year to year depending on the 

large scale ocean dynamics that determine nutrient upwelling and water quality conditions. Far 

fewer studies have occurred to link ocean conditions with marine survival, growth, and 

production of green sturgeon and eulachon, therefore it is assumed factors influencing these 

parameters are also based on large-scale forces. 

2.4 Effects of the Action on the Species and Designated Critical Habitat

“Effects of the action” means the direct and indirect effects of an action on the species or critical 

habitat, together with the effects of other activities that are interrelated or interdependent with 

that action, that will be added to the environmental baseline (50 CFR 402.02). Indirect effects are 

those that are caused by the proposed action and are later in time, but still are reasonably certain 

to occur. 

Section 1.3 of this opinion describes subsequent dredging and disposal by the Corps and all other 

entities as an interrelated action, which NMFS must consider along with the effects of EPA’s 

proposed action. Subsequent dredging and disposal actions also constitute indirect effects of the 

proposed action, since they are reasonably certain to occur. Therefore, the proposed action will 

have the following indirect effects: (1) Increased suspended sediment (fine-grained materials); 

(2) mounding; (3) reduced forage; (4) chemical contamination/exposure for OC coho salmon, 

green sturgeon, and their forage; and (5) coarse-grained materials in the water column. The EPA 

identifies the potential use of both the north and south ODMD sites in any single dredging 

season; therefore the proposed action will potentially affect 1,722 acres of the Pacific Ocean 

each dredging season. 

2.4.1 Effects to the Environment 

Water quality – suspended fine-grained solids. Interrelated actions of the proposed 

action will increase TSS within the water column repeatedly each dredging season. Based on the 

EPA’s proposed action, a maximum of 495,000 cy of dredged material could be disposed of at 
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the Yaquina ODMD sites in any one year.2 The total number of loads of dredged material 

disposed at the sites that could occur in any single dredging season is 619.2

 Each time the hopper 

dredge carries the materials out to the site and disposes of these materials, TSSs will increase. 

Disposal material is comprised of fine-grained material and larger, coarse-grained material. Finegrain suspended sediments could remain elevated in the area for longer periods than the actual 

release of dredged material. Exposure to suspended sediment plumes from dredged material 

disposal will probably be on the order of minutes to hours in duration (Wilber and Clarke 2001). 

The BA concluded the dredged disposal material is comprised of sandy material; most of the 

material will leave the water column rapidly. EPA (2011) stated dredge material will settle from 

the water column within 5 to 30 minutes, due to the relative density of the sandy dredged 

material and dispersive water column currents. The duration of the suspended sediment plume 

and the dispersion of this plume are dependent on variables such as ocean currents, size 

composition of the disposal materials, wave action, and dredge ship speed and disposal rate. 

Approximately 1,722 acres of the Pacific Ocean could be exposed annually to elevated 

suspended sediment plumes over the course of the 20 years of disposal operations. 

Suspended sediment at moderate levels, can reduce primary and secondary productivity, and at 

high levels can injure or kill adult and juvenile fish, and interfere with feeding (Bjornn and 

Reiser 1991, Servizi and Martins 1991, Spence et al. 1996). The NMFS anticipates suspended 

sediment will dissipate due to currents and wave action within a few hours. The NMFS is 

reasonably certain increases in suspended sediment levels will exceed 17 mg/l concentrations for 

the majority of the discharge field. The suspended sediment plume will be spread by the wave 

and ocean currents relative to the release location. The NMFS is reasonably certain the 

suspended sediment plume will dissipate to concentrations that are immeasurable and 

undetectable against background within 500 feet of the proposed boundaries of the ODMD sites 

within a few hours of disposal. The area will receive dredged material 619 times per year. 

Reduced primary production in the action area is not reasonably certain to occur due to the 

resulting duration (hours), concentration, and small areal coverage of the increased suspended 

sediment concentrations which result in minimal effects to primary production. 

Elevated chemical contaminants. The EPA’s proposed action includes the adoption and 

implementation of the SMMP that requires any proposed sediments for disposal to adhere to the 

procedures approved by Corps and EPA 1991 and SEF 2009. Only clean sediment may be 

disposed of at the site. The Corps conducts sediment sampling and analysis for the coastal 

projects, including Yaquina Bay, on a five-year cycle. The Corps conducted physical and 

chemical analyses at Yaquina Bay and South Beach Marina in 1980, 1986, 1990, 1991, 1995, 

2000, 2005, and 2010. Chemical analyses have shown that the sediment is typically below 

screening levels for contaminants of concern that includes metals, PAHs, and other compounds 

described in section 2.3 (Environmental baseline) of this opinion. Results for the 2010 study are 

summarized in EPA 2011. The results for 2010 were consistent with historical data. Material 

represented by these samples was determined to be suitable for unconfined, in-water placement 

without further characterization. Trace concentrations of various heavy metals, PAHs and other 

compounds will occur with the sediments, but the concentrations will not exceed those harmful 

to organisms in the action area. 
-35- 

Mounding. Past disposal of dredged materials at the interim site, the nearshore section 

103 site, and the drop zone of the northern portion of the north ODMD site have created mounds 

on the ocean floor. Section 2.3 (Environmental baseline) describes mounding that has occurred at 

the north ODMD site. The proposed action is to designate the north and south ODMD sites so 

that disposal of similar volumes of material may continue. 

Disposal capacity. Based on sediment FATE modeling, the EPA expects that the north 

and south ODMD sites will have capacity sufficient to receive, on average, 310,000 cy of 

material over a 20 year period (total capacity = 6.2 mcy) without impacting the present wave 

climate. The Yaquina north and south ODMD sites are relatively deep (112 feet to 152 feet) 

which removes material from the Newport littoral cell. Material may be re-suspended and 

brought into the littoral cell only on extreme storm events. In an annual assessment conducted by 

the Corps, they indicated to the EPA that the Yaquina north ODMD site is behaving as expected 

and will be able to receive dredged material for at least another 10 years. The Yaquina south 

ODMD site has not yet been used for disposal of dredged material and would have 20 years 

capacity (EPA 2011). 

The EPA’s and Corps’ EA (2011b) described the potential depositional thickness and areal 

coverage for different dredge ships. The estimated areal coverage of a mound resulting from a 

single load placed by the Westport (a Corps dredge ship) in 100 feet water depth is about 21 

acres with maximum mound height of 0.22 feet; however 90% of the mounded area is less than 

0.10 feet (1.2 inches). The estimated areal coverage of a mound resulting from a single load 

placed by the Yaquina in 100 feet water depth is about 17 acres with maximum mound height of 

0.12 feet; however 90% of the mounded area is less than 0.07 feet (0.84 inches). The Westport’s

dump footprint is larger aerially and thicker than the Yaquina’s dump footprint. The Yaquina’s

footprint is more uniform in terms of depositional thickness. 

Section 2.3 (Environmental baseline) of this opinion describes mounding of sediment that has 

occurred at the Yaquina north ODMD site due to disposal of dredged material. There has been 

no mounding as a result of disposal activities at the south ODMD site. Based on modeling 

conducted by the Corps presented in EPA and Corps (2011d), the seafloor at the proposed 

ODMD sites can accrete 14 feet of material without altering the wave climate. The Corps’ 

modeling also showed that using the grid placement system for disposal in one site during one 

dredging season will result in a mound that is 1.2 feet high. After 20 years, the mound height in 

one site is estimated to be 12 feet high. Since there will be a preference for disposal at the 

Yaquina north ODMD site, it will likely accrete sediment at a higher rate than the south ODMD 

site. However, the south ODMD site will be used for disposal when the north site is determined 

to have reached or is near its capacity. 

Based on the dynamic, high-energy environment found along the Oregon coast, sediment 

transport, erosion, and accretion are more dependent upon surrounding ocean forces that operate 

independent of the proposed action. Therefore, long-term mounding due to these actions is not 

likely in the future at current disposal rates. Further, annual bathymetry surveys will be 

conducted at disposal sites and compared to baseline surveys for previous year’s survey. The 

annual surveys will verify placement of material within the sites, monitor changes and trends in 

bathymetry, and ensure the site capacity is not exceeded. 
-36- 

Coarse-grained material deposition. Disposal of coarse-grain dredged material is 

reasonably certain to result in the exposure of all organisms in its descent path to adverse 

environmental conditions. This disposal could occur within both the Yaquina north and south 

ODMD sites, approximately 1,194 acres of the ocean in any single dredging season. Unlike the 

fine-grain material previously discussed, this coarse-grain material will move through the water 

column rapidly at a descent rate of 11 feet/second to start with and 7 feet/second near the end of 

the load. As water is added to the dredged material to help wash it out of the hopper, the slurry 

mixture becomes more neutrally buoyant and descends at a slower rate. It is NMFS’ judgment 

that any planktonic organisms in the path of this material will become entrained within the 

material and carried to the bottom. Pelagic species are likely to try and avoid the descending 

material, but some are reasonably certain to be entrained and taken to the ocean floor with the 

coarse-grain dredged material. A more detailed discussion of this interaction is provided in the 

“effects to the species section.” An unknown number of individuals of various vertebrate and 

invertebrate species are reasonably certain to be exposed and likely injured and killed by this 

material. 

Reduction in prey availability. These two new sites will receive the same quantity of 

disposal material as the previous smaller sites. Some accumulation of sediment will occur from 

the action. Sandy sediment will cover infaunal and epifaunal invertebrates with a layer of sandy 

sediment. The EA (EPA and Corps 2011d) estimates these areas will accrete 1.2 feet of dredged 

material after the first year and 12 feet after 20 years. However, because these accretion depths 

were calculated using an average of 310,000 cy, this estimate does not apply for years where 

dredged material from all three dredging sites in Yaquina Bay (up to 495,000 cy) are disposed of 

at the proposed ODMD sites. Accretion of dredged materials during those years is likely higher; 

however, this will likely occur infrequently (3-4 times over the next 20 years). 

Re-colonization is uncertain while the site is in active use for dredged material disposal over the 

life of the designation, an anticipated 20-year period. The specific operation of each ODMD site 

is somewhat open-ended based on the proposed action. The preferred site for disposal will be the 

north ODMD site, but disposal in both sites could occur in any year. For this analysis, NMFS 

will assume that disposal will occur in both sites annually. Therefore, the interval between 

disposal events will be from November through May, except for six days of disposal in April or 

May. The length of intervals between deposition events, particle size, currents, and 

compaction/stabilization following deposition affects the potential for re-colonization (Newell et 

al. 1998, Van der Veer et al. 1985). Rates of recovery listed in the literature range from several 

months for estuarine mud, and up to two to three years for sands and gravels (Hitchcock et al. 

1999). Re-colonization may take longer in areas with lower current (Van der Veer et al. 1985). 

This action area is indicative of a dynamic nearshore ecological zone that naturally would be 

characterized by a disturbance-based ecosystem. Disturbance-based ecosystems are have rapid 

re-colonization rates by opportunistic organisms tolerant of conditions that are physiologically 

stressful (Pemberton and MacEachern 1997). 

The EPA conducted the most recent efforts to describe the baseline densities and diversities of 

benthic infauna in June and August 2008 (see Section 2.3 Environmental Baseline). The data that 

EPA collected appeared to show that density and diversity of benthic invertebrates was reduced 

in the north ODMD site drop zone (northern half of the north ODMD site) due to disposal of 
-37- 

dredged material (EPA 2011). This reduction is reasonably certain to occur at both ODMD sites 

as disposal continues and will occur on a long-term basis. Because of the short interval between 

disposal activities, re-colonization of invertebrates will likely be slower. This effect will occur to 

the 1,722 acres of the Pacific Ocean that are the north and south ODMD sites. 

Fish species that are forage for OC coho salmon and green sturgeon may also be impacted by 

this action due to the coarse-material descending through the water column. In addition to 

various invertebrates, green sturgeon appear to be opportunistic foragers and feed on various fish 

species, such as lingcod (Dumauld et al. 2008), herring (Erickson and Hightower 2007), sand 

lace, and anchovies (Moyle 2002) that may also be adversely impacted by the disposal. Adult 

OC coho salmon may also forage on similar pelagic species. Individuals of these forage species 

may be physically harmed by the disposed dredged material. Typically these fish are smaller 

species and also less likely to avoid physical harm than larger and faster swimming species. The 

number of individuals impacted is difficult to estimate, but it is reasonably certain the number 

adversely affected would not significantly deplete the overall abundance of forage fish and 

invertebrates available to listed species in the action area because forage fish and benthic 

invertebrates are not limited in number, they are well distributed, and the impact of disposal is 

localized, affecting a small area relative to the surrounding habitat. 

2.4.2 Effects to ESA-listed species 

Presence of ESA-listed species and their spatial and temporal overlap with dredged material 

disposal activities is described as follows: 

 OC coho salmon smolts from the Yaquina River and other nearby populations (Beaver 

Creek, Alsea, Siuslaw, and Siletz rivers populations) enter the ocean in mid-February 

through June and reside in the action area and the surrounding ocean for several months 

before migrating north. Adult OC coho salmon return to the action area in late August 

and peak during September and October. Weitkamp and Neely (2002) showed that 

coded-wire tagged adults from each of the independent populations of OC coho salmon 

were recovered in the vicinity of the action area. Disposal typically occurs before adults 

have returned to the area but the Corps reports dredging could occur as late as October 

31; therefore NMFS cannot discount exposure of adults. 

 North and south migration of green sturgeon along the continental shelf and their use of 

the Yaquina River provides the potential spatial and temporal overlap between dredged 

material disposal and green sturgeon presence in the action area. 

 Adult eulachon presence in the nearshore Pacific Ocean depths within the depth range 

(112 – 152 feet) of the proposed north and south ODMD sites will overlap spatially and 

temporally with dredged material disposal. 

The Corps identified dredging and disposal may occur in Yaquina Bay from April 1 through 

October 31. Therefore, the NMFS is reasonably certain that exposure of adult and smolt OC 

coho salmon, adult and subadult green sturgeon, and adult and juvenile eulachon will occur 

during dredged material disposal associated with the proposed action. 
-38- 

As described above, mounding and chemical contamination are unlikely cause sufficient effect 

to be considered any further in this document. Water quality degradation due to fine-grain 

suspended solids and reductions in forage base for ESA-listed species may adversely affect listed 

species. The NMFS analyzes these effects further in this section of the opinion. Physical injury 

from the deposition of coarse-grain material may also adversely affect OC coho salmon, green 

sturgeon, and eulachon and is analyzed in detail. 

Water quality – suspended solids from fine-grain material. Exposure to suspended 

sediment increases as low as 17 mg/l can lead to inflammation of the gills and respiratory stress 

in juvenile OC coho salmon (Berg and Northcote 1985). The NMFS is reasonably certain 

suspended sediment concentrations caused by fine-grained dredged materials will exceed 17 

mg/l, resulting in injury to juvenile OC coho salmon. However, NMFS is also reasonably certain 

yearling OC coho salmon will not remain in the sediment plume for a period (4 to 96 hours) 

sufficient to elicit an adverse physiological or behavioral response. The duration and dispersion 

of the suspended sediment plume are dependent on variables such as ocean currents, size 

composition of disposal materials, wave action, dredge ship speed, and disposal rate. The NMFS 

is reasonably certain turbidity will drift approximately 500 feet outside of the ODMD site and 

cover approximately 1,722 acres, which includes both the north and south ODMD sites. The 

EPA stated that dredged material disposal could occur at both disposal sites in any one year.3

Movement by salmonids to avoid sediment plumes has been observed in lotic environments 

(McLeay et al. 1984, 1987, Sigler et al. 1984, Lloyd 1987, Scannell 1988, Servizi and Martens 

1991). In the ocean, localized sediment plumes from disposal will only affect the immediate 

ocean environment and should not inhibit yearling OC coho salmon from moving away from 

suspended sediment plumes. Therefore, while effects to some OC coho salmon may occur from 

exposure to project-related sediment plumes, these effects will not occur on a spatial or temporal 

scale that will significantly disrupt their normal behavioral patterns. The physical effects from 

exposure to elevated suspended sediment levels are insignificant to yearling OC coho salmon. 

The NMFS is reasonably certain the increased concentrations of suspended sediment are unlikely 

to physically harm or disrupt adult OC coho salmon normal behavioral patterns and are 

insignificant. 

Adult and subadult green sturgeon are far less sensitive to suspended sediments than salmonids 

and elevated suspended sediment concentrations will result in insignificant effects to green 

sturgeon. Subsequently, green sturgeon will not display a significant behavioral or physical 

response because of their higher tolerance to suspended solids. Green sturgeon usually inhabit 

environments with higher suspended sediment concentrations than do salmonids. Erickson and 

Hightower (2007) observed green sturgeon typically occupying depths from 130 to 230 feet and 

making occasional rapid ascents toward the surface during their migration journey. The 

maximum depth in the action area is 152 feet so green sturgeon are likely to occupy the lower 

regions of the water column. If green sturgeon are occupying the lower reaches of the water 

column they will likely be exposed to lower turbidity levels because much of the fine material 

will have suspended higher in the water column. Because green sturgeon have higher tolerances 

for suspended sediment and the suspended sediment is in the upper water column, green 

sturgeon’s normal behavioral patterns are unlikely to be disrupted by suspended fine sediment. 

Therefore, any effects of the proposed action on green sturgeon are expected to be insignificant. 
-39- 

Research pertaining to the concentrations and duration of exposure resulting in adverse effects to 

eulachon from increased suspended sediments is lacking. The NMFS is not aware of any studies 

or research relating the two. However, the effects of increased suspended sediments to eulachon 

are likely similar to those observed by Berg and Northcote (1985) for juvenile coho salmon. 

Eulachon are also likely to exhibit similar avoidance strategies as those shown by salmonids 

avoiding suspended sediment plumes. In the ocean, localized sediment plumes from disposal will 

only effect the immediate ocean environment and should not inhibit eulachon from moving away 

from suspended sediment plumes. It is likely that eulachon exposure to fine-grained suspended 

sediments will occur, but unlikely that they will experience physical harm or disruption of 

normal behavior patterns because exposure will not occur at a spatial or temporal scale that is 

significant enough to elicit an adverse response. Therefore, the effects of fine-grained suspended 

sediments to eulachon are insignificant. 

Prey availability. Yearling OC coho salmon and adult and juvenile eulachon forage on 

zooplankton and other planktonic species that occur in the action area. The interrelated actions 

are unlikely to reduce the overall abundance of these prey species. Green sturgeon forage on 

benthic invertebrates in the action area. Impacts of dredged material disposal on the abundance 

of benthic invertebrate species that are forage for green sturgeon are unlikely to significantly 

limit the overall forage availability for green sturgeon. The action is also unlikely to limit the 

availability of forage fish species to a level that would limit survival or growth potential of green 

sturgeon or adult OC coho salmon. The NMFS is reasonably certain the reduction in prey species 

due to interrelated actions is insignificant because: (1) Prey abundance is determined by larger 

scale physical and biological factors; (2) the abundance of prey available to green sturgeon, OC 

coho salmon, and eulachon throughout their range in the Pacific Ocean is great; and (3) the 

action area is small compared to the available surrounding habitat for these prey species in the 

Pacific Ocean. 

Physical injury. Previous sections of this opinion describe the temporal and spatial 

overlap of dredged material disposal and adult and juvenile OC coho salmon, adult and subadult 

green sturgeon, and adult and juvenile eulachon. The factors important to assessing the 

likelihood for this disposed dredged material to physically adversely affect the aforementioned 

ESA-listed species and life stages include: (1) Avoidance response to the ship; (2) avoidance 

response to the disposal material; (3) discharge field size; (4) fish swimming speed; 

(5) material’s descent rate; (6) quantity of material; (7) material weight; and (8) physical 

interaction of the fish and the material. The avoidance response from either the ship or the falling 

sediment will be considered first because if the fish can avoid the exposure, then there would not 

be physical consequences. If the fish cannot avoid the material, then the other factors are 

important for the response to this exposure. This discharge occurs within the ODMD sites only; 

therefore the impact would occur within the 1,194 acres. 

Ship avoidance. For a fish to avoid the disposal material, it must first detect and react to 

either the ship or the disposal material descending around them, and then must react quickly 

enough to avoid direct exposure to the material. Behavior studies related to other water vessels 

would suggest that unless the juvenile OC coho salmon are near the surface, they are unlikely to 

react to a ship passing above them (Satterthwaite 1995). Fernandes et al. (2000) contend fish do 

not avoid survey vessels in their study of vessel avoidance by herring. There is no clear 
-40- 

conclusion with this premise based on study results for other species (Gerlotto and Freon 1992; 

Misund 1993, Misund et al. 1996, Jorgensen et al. 2004). In these other studies, vertical and 

horizontal avoidance responses were observed where some fish reacted to the noise of the vessel 

by diving, others moved horizontally from the noise, and some moved away ahead of the vessel. 

Based on the conflicting results, the NMFS is reasonably certain not all yearling OC coho 

salmon, green sturgeon, or eulachon will react to the vessel and move away from the discharge 

field. 

Avoidance to disposed material. It is unknown whether the OC coho salmon, eulachon, or 

green sturgeon will elicit an avoidance response to the disposed material. The Corps (2005) 

speculated pelagic salmon would not be adversely affected by disposal material, but the NMFS is 

not aware of any research or observations to document yearling OC coho salmon, eulachon, or 

green sturgeon response to this material. The NMFS is reasonably certain the fish will detect the 

descending material and will attempt to evade the material, because the fish will likely perceive 

the material as a threat. Based on the observed ship avoidance response research, it is the NMFS’ 

judgment the likely initial movement by the fish will be to dive and then initiate horizontal 

evasion. The determining factor then will be whether the fish can swim fast enough to move out 

of the discharge field. 

Discharge field size. The size of the discharge field is primarily determined by the size of 

the dredge material disposal vessel, the volume of disposal material, the depth of water, and the 

length of the disposal run, although water depth appears to be the most significant variable in 

determining overall discharge field size. In-water disposal by hopper dredge will create a 

discharge field from the bottom of the vessel’s hull to the ocean or estuary floor. The depths of 

the Yaquina ODMD sites range from 112 to 152 feet. 

As a hopper dredge releases dredged material, it falls through the water column and mixes with 

the ambient water to create a plume. This process is called convective descent. The greatest risk 

to pelagic fish species occurs when they interact with this descending column of dredged 

material. The discharge field during each disposal run will vary based on the depth of the 

disposal site; with the volume of water exposed increasing with depth. Because actual disposal 

locations within each ODMD site will vary based on site specific bathymetric conditions at the 

time of disposal, for the purposes of this consultation, estimates of the volume of water exposed 

to the convective descent column have been calculated by the Corps the Yaquina based on the 

typical volume of dredged material disposed in 60 feet of water. The beam of the dredge ship 

Yaquina, the ship primarily used for dredging Yaquina Bay, is approximately 58 feet wide. 

When the depth of the disposal site is -60 feet, the disposal plume will begin at approximately -

16 feet (bottom of hull) and be approximately 10 feet in diameter. As the plume descends to the 

bottom, the radius of the plume will be approximately 92 feet (EPA 2011). This discharge field 

will extend along the travel route of the dredge ship. The estimated areal coverage resulting from 

a single load placed by the Yaquina in 100 feet of water is about 21 acres (EPA and Corps 

2011d). 

The amount of dredged and subsequently disposed material depends on many factors including 

the sediment characteristics and dredging conditions. While the specific volume of sediment 

dredged may vary at any given time because of these variables, the goal of any dredging 
-41- 

operation is to work as efficiently as possible to complete the job. Therefore, for the purposes of 

this consultation, a “typical” volume of dredged material disposed during a single disposal event 

is considered approximately 800 cy for the Yaquina. The volume of water exposed during 

disposal of this amount of material then is approximately 25,000 cubic meters (m3

) for the 

Yaquina. 

Spatial overlap between ESA-listed fish and discharge field. The distance from the 

bottom of the hopper dredge to the surface of the water will vary depending on the specific 

dredge and how loaded the dredge is. This distance will change as the hopper dredge discharges 

material into the disposal location. Fish occurring near the water surface, above the discharge 

doors, will be safe from exposure to the material. However, the hopper dredge will start rising as 

it releases dredged materials thereby increasing the area of the discharge field. Yearling 

salmonids have been shown to use the upper 20 to 25 feet of the water column, although they 

may use water column depths ranging from 22 to 37 feet (Carlson et al. 2001, Beeman et al. 

2003). Off of the Oregon coast, surface trawls that sampled from the surface down to 54 feet in 

depth captured yearling OC coho salmon (Brodeur et al. 2004). Green sturgeon may use various 

portions of the water column, but are likely at a much deeper depth than the OC coho salmon. 

Erickson and Hightower (2007) observed green sturgeon typically occupying depths from 130 to 

230 feet, making occasional rapid ascents toward the surface. Barraclough (1964) describes the 

depth range at which eulachon were caught as bycatch in mid-water trawls and pink shrimp 

trawls from 72 to 630 feet. Hay and McCarter (2000) showed the offshore distribution of 

eulachon in British Columbia as determined in research trawl surveys, which indicate that most 

eulachon were taken at around 328 feet, although some were taken as deep as 1,640 and some 

less than 33 feet. Groundfish surveys that captured eulachon (Weinberg et al. 1994, Wilkins et 

al. 1998, Shaw et al. 2000, Weinberg et al. 2002) occurred at depths of 180 to 600 feet along the 

continental shelf. 

Swimming speed of ESA-listed fish. Successful avoidance will depend on the swimming 

speed of the fish, the distance it must travel to avoid the discharge field, and the descent speed of 

the material. Although the Corps theorizes that the juvenile OC coho salmon would either avoid 

the dispersal area or the physics of the disposal plume would displace the fish laterally, no direct 

evidence supports such an assertion (Corps 2005). The Bell Fisheries Handbook (1990) describes 

three swimming speeds including: (1) Cruising speed – speed that can be maintained for long 

periods of time (hours); (2) sustained speed – speed that can be maintained for minutes; and (3) 

darting speed – speed that is a non-sustainable single effort lasting for only five to ten seconds. 

Yearling OC coho salmon are approximately five inches in length when upon ocean entry from 

the Oregon’s coastal river basins. Their darting speed, the likely response when the disposal 

material is detected, is estimated at 4 to 5 feet/second (Bell Fisheries Handbook 1990). The 

darting speed of adult OC coho salmon may exceed 20 feet/second (Bell Fisheries Handbook 

1990). The darting speed of green sturgeon is unknown. Niggemeyer and Duster (2003) 

estimated cruising speed, a sustained swimming speed, for green sturgeon at 1 body 

length/second. Darting speed would likely be higher than this, possibly twice as fast. Adult green 

sturgeon captured in various research studies range from 3.9 to 7.4 feet in length (Moser and 

Lindley 2007, Erickson and Webb 2007). Juvenile green sturgeon may enter the ocean 

environment when they are 2- to 3-years old and possibly 2 feet long (Adams et al. 2002). Based 

on the body lengths, darting speed for adult green sturgeon of this reported size would be 8 to 15 
-42- 

feet/second (2 body lengths/second) and 4 feet/second for small subadults. Darting speed for 

eulachon has not been studied to provide an estimate; however, Swanson et al. (1998) 

determined that critical swimming velocity7

 for delta smelt (Hypomesus transpacificus) was 

about 6.6 body lengths/second. Eulachon of similar size to the delta smelt studied by Swanson et 

al. (1998) likely swim at similar speeds, therefore, NMFS will use this velocity for the eulachon 

analysis. This comparison may not be optimal, but represents the best available scientific 

information at this time. Darting speed is likely higher than 6.6 body lengths/second, possibly 

two times as fast or 13.2 body lengths/second. Based on body lengths, juvenile eulachon would 

have darting speeds of 1.3 to 4.4 feet/second. Adult eulachon would have darting speeds of 4.4 to 

10.8 feet/second. 

Relationship between the discharge field and ESA-listed fish swimming speeds. The EPA 

and Corps predict the initial plume velocity just before impact will reach 11 feet/second. They 

also predict material last to leave the hopper to have a maximum velocity of 7 feet/second 

because the slurry mixture would have a greater proportion of neutral buoyant water. Assuming a 

central location in the discharge field (29 feet from edge of the field) and direct movement to the 

edge of the field, it would take a yearling OC coho salmon 5.8 seconds to reach the plume edge. 

The maximum time a fish can sustain a darting speed is 5 to 10 seconds. Yearling OC coho 

salmon may not be able to reach the edge of the plume in the allotted time, even if they choose 

the correct direction and move directly toward the edge. With the material descending at 7 to 11 

feet/second, it will be challenging for yearling OC coho salmon to avoid the descending plume. 

In five seconds the plume will descend 35 to 55 feet. Conversely, adult OC coho salmon have a 

high likelihood of reaching the edge of the plume due to their speed. Based on a central location 

and given a darting speed of 20 feet/second, an adult OC coho salmon would reach the edge of 

the 58-foot wide field in slightly over 1 second. 

Adult green sturgeon, with darting speeds of 8 to 14 feet/second, are likely to evade the 

descending material. Given the same conditions previously described and similar response, adult 

green sturgeon may reach the edge of the discharge field in 2 to 3.6 seconds. In 3.6 seconds, the 

plume will descend 25 to 40 feet. Younger and smaller green sturgeon may not be capable of 

reaching the edge. Small subadult green sturgeon may be closer to 2 feet long, therefore their 

speed would be possibly 4 feet/second, similar to that of the yearling OC coho salmon; therefore 

NMFS concludes with reasonable certainty younger green sturgeon could be exposed and 

physically harmed by this material. 

Adult and juvenile eulachon could be exposed and injured or killed by disposed dredged 

material. Adult eulachon darting speeds range from 4.4 to 10.8 feet/second. Assuming the same 

descent rate and width of the plume some adult eulachon would not make it to the edge of the 

plume before the dredged material engulfed them. It would take adult eulachon from 2.7 to 6.6 

seconds to reach the edge of the plume. In 6.6 seconds, the plume would descend 46 to 73 feet 

from the hopper dredge. Juvenile eulachon darting speeds are estimated to range from 1.3 to 4.4 

feet/second. At these speeds, it would take juvenile eulachon 6.6 to 22.3 seconds to reach the 

edge of the plume. The plume descent rate is such that before 22.3 seconds, the material will hit 

the ocean floor in the deepest parts of the ODMD sites. Therefore, some adult and most juvenile 

 

7

 Critical swimming velocity is the maximum velocity that a fish can maintain for a period. This velocity is higher 

than sustained swimming velocities and eventually results in fatigue of the fish. 
-43- 

eulachon exposed to the disposal plume will not be able to evade the descending plume and will 

be injured or killed by descending material. 

Given that the fish cannot sustain darting speeds for longer than five seconds; the fish may also

have to rely on sustained speed to avoid the plume. The sustained speed of a five-inch yearling 

OC coho salmon is predicted to be 2.1 feet/second (Bell Fisheries Handbook 1990). It would 

require almost 14 seconds for the fish to reach the edge of the 58-foot wide plume if they started 

in the center of the plume. In 14 seconds, the plume would descend 98 to 154 feet. The Yaquina 

ODMD sites range in depth from 112 to 152 feet deep so the plume could hit the floor of the 

disposal area before a yearling OC coho salmon could evade. The expectation is that given these 

swimming speed challenges and descent rate, many yearling OC coho salmon are not going to be 

able to avoid the disposal plume. A confounding problem is that these yearling OC coho salmon 

may be exhibiting schooling behavior; therefore, numerous fish may be exposed at one time. 

Typical avoidance response may also include an initial dive to avoid the material and then 

horizontal movement, thus losing time to evade the descending material. It is likely that adult OC 

coho salmon can evade the sediment plume, but some of the yearling OC coho salmon will not. 

Evasion by green sturgeon is likely more probable than OC coho salmon due to their expected 

location in the water column. Whether relying on darting or sustained speed the green sturgeon 

occupying the deeper depths of the water column have more time to detect the descending 

sediments and initiate an avoidance response. It is assumed that adult green sturgeon, given their 

larger size, faster swimming speed, and inhabiting deeper depth will avoid the discharge plume. 

The youngest and smallest green sturgeon may not escape the falling sediment. These younger 

subadults that may only be 2 feet in length would have a sustained swimming speed of 2 

feet/second and may still not be able to successfully avoid the descending plume, despite their 

deeper depth location. The NMFS is reasonably certain that adult and larger subadult green 

sturgeon are unlikely to be physically harmed because these individuals will avoid the 

descending sediments. Smaller individuals, those near to the 2-foot length, are more likely to be 

unsuccessful in avoiding the descending material and this action poses physical risk to any of 

these individuals directly exposed to the disposed dredge material. 

The effects to eulachon are likely similar to those that occur to juvenile OC coho salmon. 

Juveniles and adults that cannot reach the edge of the plume within five seconds using darting 

speeds must rely on slower swimming speeds to reach the edge of the plume. Critical swimming 

speed, which is faster than sustained speed, is estimated for juvenile eulachon at 0.66 to 2.2 

feet/seconds and 2.2 feet/second for adult eulachon that did not reach the edge of the plume with 

their darting response. If starting from the center of the 59-foot wide disposal plume, it would 

take juvenile eulachon 13.2 to 44 seconds to reach the edge of the disposal plume. It would take 

adults 13.2 seconds to reach the edge from the center of the plume. The disposal plume will have 

descended to 92.4 feet to the ocean floor in that time range. Given the distribution of eulachon 

throughout the water column, individuals occupying shallower depths have a higher likelihood of 

becoming entrained of physically injured or killed by the descending disposed dredged material. 

Those individuals occupying deeper depths of the action area are likely to have more time to 

detect and react to the descending discharge plume. It is reasonably certain that some juvenile 

and smaller adult eulachon exhibiting slower darting speeds (at or near 4.4 feet/second) relative 
-44- 

to their position near the disposal plume will not be able to avoid the descending disposed 

dredged material. 

Dredged material disposal quantity and weight. Disposal quantities and discharge time 

are important variables to consider while assessing the likelihood for OC coho salmon juveniles, 

small subadult green sturgeon, and eulachon to be adversely affected through a physical injury 

from disposal material. Based on the previous discussion, NMFS concludes exposure to this 

disposed material is inevitable for yearling coho salmon, small subadult green sturgeon, and 

juvenile and adult eulachon. The Yaquina dredge capacity is 1,042 cy, however, the EPA used a 

value of 800 cy per load as an estimate of a volume in a typical disposal load for the purposes of 

calculating the volume of water exposed to the disposal plume. A cubic yard of wet sand may 

weigh as much as 4,000 pounds (lbs). At 800 cy of sand, a maximum of 3,200,000 lbs of 

material may be discharged during a single event. If a typical load on the Yaquina is discharged 

over a period of five minutes, this equates to over 10,000 lbs per second of discharge. The 

amount and weight of this material is significant for a small fish to resist from being entrained by 

the descending material and dragged down to the ocean floor. The quantity of dredge material 

displaces a large volume of water; therefore, if some fish are pushed ahead of the discharge 

plume they would be entrained within the vortices of the turbulent flow. In order to assess the 

physical risk posed by the exposure to disposed dredge material the physical interaction between 

the fish and the material is of most interest. 

Physical interaction between ESA-listed fish and disposed dredged material. The Corps 

theorizes in their assessment entitled Parameters Describing the Convective Descent of Dredged 

Material Placed in Open Water by a Hopper Dredge, which was developed by the Corps in 

March 4, 2005, as an amendment letter to another dredge disposal consultation (refer to NMFS 

No.:2004/01041, Corps 2005), that the fish that come into contact with the material and are 

unable to escape will either resist the material and be exposed to a drag force caused by the 

material or the fish will not resist and will be displaced by the material plume. If the fish does not 

resist, the Corps theorized, a boundary layer at the leading edge of the plume would reduce the 

likelihood of the fish becoming entrained in the material plume. If the fish does become 

entrained, then the Corps expects the fish will be carried with the plume toward the bottom. In 

that assessment, the Corps’ conclusion for any of the scenarios is that it is unlikely the fish would 

be adversely affected because the fish would: (1) Allow the material to move around them and 

only be pulled down by the material but not injured; (2) be pushed ahead of the plume due to a 

boundary layer and then laterally as the plume reached the ocean floor; or (3) be moved aside by 

the material. The NMFS considers that a high degree of uncertainty exists regarding the response 

and risk of fish exposed to disposed materials. Without substantial supporting evidence the 

Corps’ assessment can be considered representative of possible outcomes, but not all outcomes. 

The NMFS considers that enough uncertainty exists regarding the physical interaction between 

fish and disposal material that it is reasonably certain to conclude that listed species are subject 

to physical risk. Additional outcomes include a fish being carried along with the downward 

movement of the sediment and buried under the deposited material and the physical abrasion of 

their epidermis. 
-45- 

Several adverse physical consequences for fish may occur, even given the Corps’ possible 

outcomes. The Corps’ first outcome described above would require the fish to spend a length of 

time surrounded by dredge material and would result in the respiration of this material past the 

gills. Very high concentrations of suspended sediments will occur within the water column of the 

plume. Physical damage to gill membranes is the likely result of this exposure to the material and 

the subsequent increased probability of indirect effects of disease and infection would lead to 

increased mortality. The Corps’ second and third outcomes described above are also likely to 

lead to similar adverse physical effects. The fluid dynamics and characteristics of the plume 

result in significant turbulence of the water along the edge and within the plume. A fish caught in 

this turbulence and the collapse phase of the discharge field will be entrained in an environment 

with very high suspended sediment concentrations for a time that would require the fish to 

respire this damaging sediment. In addition to the gill damage, some fish are likely to receive 

abrasion from material passing around them that would remove some of the protective epidermal 

mucus or when they are forced down to the ocean floor, which is most likely the point where 

mucus would be removed. Whether the fish is forced into the ocean floor or pushed along the 

bottom with the collapsing front of the plume, the fish will likely have physical abrasions that are 

susceptible to secondary infections. Another possible outcome with these scenarios is the 

disorientation of a fish caught in the turbulence of the plume. These fish are likely to be more 

susceptible to predation due to the disorientation. The NMFS is reasonably certain exposing 

yearling OC coho salmon, smaller green sturgeon, and eulachon to disposed material could result 

in increased predation or physical harm to the fish from either becoming entrained and buried in 

the material when it settles on the ocean floor; respiring high concentrations of suspended 

sediments; being physically abraded by the material; and/or harmed by collision with the bottom 

substrate. 

Numbers exposed. The NMFS is required to evaluate the magnitude of the adverse effect 

to determine the potential level of mortality and to assess the potential for jeopardy. The 

magnitude of the adverse effects from dredged material disposal will be evaluated separately. 

The following approaches are intended to assess the upper limits of the magnitude for the 

purposes of determining the potential that the proposed impacts are significant to result in 

jeopardy to ESA-listed fish species. However, it is important to note that due to the uncertainty 

associated with these methods, these values should be considered estimates and are not precise. 

There is a range of adverse effects based on day-to-day abundance of yearling coho salmon in 

the action area at the time of disposal. This analysis builds upon conservative assumptions for 

understanding the potential magnitude of the adverse effects due to dredged material disposal 

resulting from the proposed action. 

During disposal, the primary exposure pathway for pelagic fish occurs during an encounter with 

the sediment plume associated with the convective descent phase of disposal. The volume of 

sediment disposed per event is variable, however work is typically conducted in the most 

effective manner possible and therefore, we estimated that a typical disposal load consists of 800 

cy for the Yaquina. Using these volumes, we then calculated the number of disposal loads that 

would be necessary to complete dredging work at Yaquina Bay based on the maximum 

anticipated disposal volume provided by the EPA. The EPA proposed a maximum amount of 

dredged material disposed at the Yaquina ODMD sites of 495,000 cy that includes disposal 

activities occurring from the Corps and all other entities of Yaquina Bay that may need to 
-46- 

dispose of dredged material. Using the typical load amount of 800 cy for the Yaquina dredge, 

dividing this into the maximum amount of dredged material disposed at the Yaquina ODMD 

sites yields approximately 619 disposal loads per dredging season. 

To estimate likely numbers of yearling OC coho salmon adversely affected by dredged material 

disposal, NMFS used information obtained from Global Ocean Ecosystem Dynamics 

(GLOBEC) and the Northwest Fisheries Science Center (NWFSC) cruises off of northern 

California and Oregon coasts (NWFSC 2000 and 2002). Estimates for small subadult green 

sturgeon and eulachon will rely on best judgment based on the use of this area by these species. 

The NMFS recognizes that these estimates are not exact; however, they provide a relative 

estimate of the potential impact from ocean disposal, allowing NMFS to better evaluate these 

impacts and inform the final jeopardy analysis. 

The NMFS assumes some of the individuals in the disposal area will avoid direct exposure to the 

discharge plume by: (1) Avoiding the ship; (2) randomly being positioned in the action area 

away from the direct path of the ship; (3) exhibiting some avoidance to the discharge field due to 

their position in relation to the discharge plume; and (4) being randomly near the edge of the 

discharge field thereby facilitating avoidance. However, at least some of these fish directly 

exposed to the convective descent phase of in-water disposal will be adversely affected, likely 

leading to mortality for those individuals caught directly in the plume because they will 

experience injury and death due to this exposure to the discharged dredged sediments. 

In 2000, more OC coho salmon yearlings were captured in the trawls in August than June 

(Brodeur et al. 2004). In the combined data reviewed for the two years of trawl data, the 

abundance of OC coho salmon yearlings varied and for most stations the average abundance was 

highest during June (NWFSC 2000 and 2002). For this analysis, we considered June densities 

represented the highest abundance based on the outmigration of OC coho salmon smolts from the 

rivers and the combined two years of ocean trawl data. Based on NWFSC (2000) and (2002) data 

an estimated 45 OC coho salmon smolts/1,000,000 m3

 may be present in the nearshore Pacific 

Ocean near Yaquina Bay. The total maximum number of fish that may be injured or killed by a 

disposal event in the action area is a function of water volume affected by disposal and density of 

OC coho salmon smolts in the ocean. The disposal plume from the dredge Yaquina will affect 

approximately 25,000 m3 of water. Therefore, on average a single disposal event from the 

Yaquina will adversely affect 1.1 OC coho salmon yearlings. No evidence exists to provide an 

assessment as to whether individuals from adjacent ocean areas may move into or out of the 

ODMD sites between disposal loads, whether within the same day or different days. If fish leave 

the area due to an avoidance of the discharge field, some of these individuals, or others nearby, 

are likely to reoccupy the disposal site after some short, but uncertain period of time; it is likely 

that the longer the time between disposal loads the higher the probability that the ODMD sites 

will be reoccupied to the base abundance. When disposal is occurring during the months when 

OC coho salmon smolts are entering the ocean, there are a higher likelihood these individuals 

may enter the ODMD sites immediately upon ocean entry. Assuming the disposal areas 

repopulate between loads the total maximum yearling OC coho salmon exposed to the disposal 

activities is the number of individuals affected by a single disposal event multiplied by the 

number of disposal events. For this consultation the number of disposal loads (619) was based on 

the maximum proposed amount of material disposal (495,000 cy) divided by the typical load 
-47- 

amount disposed by the Yaquina dredge (800 cy). The number of yearling OC coho salmon 

exposed to dredged material disposal per dredging season is 697. Because of year-to-year 

variability in the amount of material and the number of loads needed to dispose of dredged 

material, the number of yearling OC coho salmon exposed to dredged material disposal will also 

vary annually. This estimate builds upon conservative assumptions for the purpose of 

understanding the potential magnitude of the adverse effects and constitutes the maximum 

number of individuals likely exposed. Exposure of 697 yearling OC coho salmon in a single 

dredging season is likely every five to eight years. In other years, when the maximum amount of 

material is not disposed of at the proposed sites, the number of yearling OC coho salmon 

exposed is approximately 522 (based on 370,000 cy of material). The NMFS assumes 100% 

mortality for the number of individuals exposed to dredged material disposal. 

Yearling OC coho salmon individuals from the Yaquina and Alsea rivers and Beaver Creek 

populations will make up the total number of those injured or killed by the disposal of dredged 

material. As previously presented in the section 2.2.1 (status of the species) of this opinion, 

NMFS calculated estimates of yearling OC coho salmon for each population. The yearling OC 

coho salmon present in the action area represent mostly a composite of the three populations. 

Assuming equal impact across all three populations, the average number of yearlings that may be 

entering the ocean per year is 247,796 (average for combined Yaquina, Alsea, and Beaver Creek 

populations 1995 to 2010). The lowest and highest number of yearlings during this time frame 

was 17,284 and 545,381 individuals, respectively. The total maximum mortality from disposal of 

dredged material (697) represents 0.28% (range 0.13% to 4%) of the combined Yaquina, Alsea, 

and Beaver Creek populations for those given years. The NMFS is reasonably certain that 4% is 

an overestimate because yearling coho salmon abundance in the action area would be 

proportionately lower when there are only 17,284 yearling coho salmon produced from the three 

populations, the density of yearling OC coho salmon in the action area could be significantly 

lower than the densities reported by NWFSC (2000) and (2002). 

The total abundance of green sturgeon is unknown (Adams et al. 2007), therefore the abundance 

of the green sturgeon within each of the ODMD sites is unknown but likely to be very low. 

Lindley et al. (2008) tracked the migrating tagged green sturgeon along the west coast (Figure 

4). It is apparent green sturgeon are migrating along the Oregon coast, but whether they actually 

enter the action area is unknown. It is also unknown whether the younger smaller individuals of 

green sturgeon migrate to the Yaquina River area. In addition to their exact location, these 

migrating fish are likely moving through the area at a high rate of speed (Lindley et al. 2008) and 

therefore not likely to stay within an individual action area very long. The most likely migration 

scenario where green sturgeon might enter the action area would be for green sturgeon that are 

headed into Yaquina River estuary. The NMFS is unable to estimate the number of green 

sturgeon adversely affected by this action, but expects this number to be low because: (1) 

Limited information exists on the number of green sturgeon using the Yaquina River; (2) 

migrating green sturgeon spend limited time in one area as they move from estuary to estuary 

and are possibly further offshore; (3) the green sturgeon do not spawn in any of Oregon coastal 

river basins, and therefore, small juvenile green sturgeon will not be present; and (4) the relative 

size of the action area compared to the range of green sturgeon is extremely small. Nonetheless, 

the NMFS is reasonably certain adverse effects will occur to some smaller subadult green 

sturgeon at the time of the material disposal. 
-48- 

Eulachon abundance across the range of the entire DPS is not well known. Presence and 

abundance in the action area is dependent on marine distribution patterns of eulachon that are not 

well known, but a previous study (Beacham et al. 2005) has shown that eulachon likely travel 

large distances from their natal stream during the ocean part of their life cycle. Marine 

distribution of eulachon is partly dependent on the location and abundance of spawning 

populations of eulachon. We previously determined that eulachon are reasonably certain to occur 

in the action area, but because of the lack of information on eulachon abundance, we cannot 

accurately quantify the number of individuals that could potentially be present in the action area. 

The most likely scenario for eulachon presence in the action area is a school foraging within or 

migrating through the action area. Eulachon are a pelagic species and likely exhibit schooling 

behavior when in the ocean. When they are present in the action area, it is likely that many 

individuals will be concentrated in a small area. Based on the above analysis, exposure of 

eulachon to disposed dredged material will occur; however, the frequency of exposure is likely 

low. Known spawning populations of eulachon on the Oregon Coast are the Columbia River, 

Tenmile Creek (near Yachats, Oregon), and the Umpqua River. Presumably, eulachon off the 

Oregon Coast are mostly from the Columbia River because populations south of there are 

thought to have severely declined (Gustafson et al. 2010). The NMFS cannot predict the number 

of eulachon injured or killed by disposed dredged material, but expects this number to be small 

because: (1) There is little information explaining the distribution and abundance of eulachon in 

the action area; (2) known spawning populations are north (Columbia River – greater than 110 

miles) and south (Tenmile Creek and Umpqua River – greater than 24 miles) of the action area, 

limiting the number of eulachon potentially present in the action area; (3) schooling eulachon 

will be actively foraging and/or migrating and will not be present in the action area for long 

periods of time; and (4) the relative size of the action area compared to the range of eulachon is 

extremely small. 

Summary of effects to OC coho salmon. Exposure of adult and yearling OC coho salmon 

to disposed dredged material will occur because of the proposed action. The risk to adult OC 

coho salmon individuals is low based on their faster swimming speed and ability to avoid the 

descending sediment plume. Some yearling OC coho salmon will, however, be exposed to the 

descending dredged material plume. Yearlings will exhibit minimal avoidance behavior from the 

ship and, depending on their location in the plume, may not be able to swim fast enough to avoid 

dredged material. The NMFS is reasonably certain dredged material disposal will result in injury 

or death to up to approximately 697 yearling OC coho salmon per year from: (1) Becoming 

entrained and buried in the material when it settles on the ocean floor; (2) respiring high 

concentrations of suspended sediments; (3) being physically abraded by the material; and (4) 

collision with the bottom substrate. The disposal of dredged material will injure or kill 

individuals from the three populations of the mid-coast stratum of OC coho salmon. 

Yearling OC coho salmon individuals injured or killed by the disposal plume are from the 

Yaquina and Alsea rivers and Beaver Creek populations of OC coho salmon. The numbers of 

yearling OC coho salmon injured or killed from dredged material disposal (697 or 522) is related 

to the numbers of yearling OC coho salmon outmigrating from each population and the location 

of the population in relation to the action area. No population should be impacted inequitably, 

such that the total impact will be spread between the three populations. Mortality that could 

occur from dredged material disposal represents 0.28% of the average number of yearling OC 
-49- 

coho salmon produced in the Yaquina, Alsea, and Beaver Creek populations. The effects on 

abundance and productivity at the population scale will be insignificant because such a small 

portion of each population will be affected. Therefore, effects on population abundance and 

productivity will not be measurable or meaningfully. 

Summary of effects to green sturgeon. Some individual green sturgeon will experience 

effects from the discharge of these dredged sediments from the hopper dredge. Adult and 

subadult green sturgeon may inhabit the action area during their migration from their natal rivers 

in California to northern waters in Oregon, Washington, and Canada. Green sturgeon use the 

Yaquina River estuary and due to the close proximity of the action area to the Yaquina River, a 

possible overlap in time and space with the disposal activity has some likelihood of occurring. 

The potential use, behavior and abundance of green sturgeon are not known for the action area. 

Based on general abundance, capture information, and migration routes green sturgeon may use 

the action area. For those that do occur within the action area, the exposure of green sturgeon to 

the disposal material was determined to be inevitable based on the expectation that the fish will 

not exhibit avoidance behavior from the ship. Larger adult and subadult green sturgeon will 

successfully evade the sediment plume without significant physical injury that would result in 

death because their faster swimming speed and occupation of deeper water depths will facilitate 

evasion. Younger, smaller subadults that are approximately 2 feet or less in length have a higher 

risk than the larger fish due to their slower swimming speed. The NMFS is reasonably certain 

smaller green sturgeon exposed to the disposed dredged material will have a high likelihood of 

experiencing physical injury and death. Although the NMFS is unable to estimate the number per 

year killed, NMFS is reasonably certain this number is low. 

The effects on abundance and productivity at the population scale will be insignificant because 

such a small number of individuals could be exposed to the activity. The NMFS is reasonably 

certain the proportion of the population that will be affected is small based on the research results 

that have demonstrated large numbers of green sturgeon are present in Canadian waters, the 

Washington estuaries and the Columbia River during the summer months (Lindley et al. 2008, 

Moser and Lindley 2007, Adams et al. 2007, Grimes 2006). Therefore, effects on abundance, 

productivity or genetic diversity will not be measurable or meaningfully expressed at the 

population scale. 

Summary of effects to eulachon. Adult and juvenile eulachon exposure to dredged 

material disposal will occur. Adult eulachon that cannot swim fast enough to avoid the 

descending dredged material plume and juvenile eulachon will experience adverse effects and 

injury and/or death from disposed material. Eulachon will likely exhibit avoidance behavior 

when the ship is detected and move away from the dredge ship, but some individuals will 

remain. The NMFS determined that some eulachon would experience exposure to disposed 

dredged material. The risk to eulachon includes physical injury from either becoming entrained 

in the material when it settles on the ocean floor; being physically abraded by the material; 

and/or injured by collision with the ocean substrate when the individual is advected with the 

descending material. 

The effects on abundance and productivity at the population scale will be insignificant because 

the number of individual eulachon that will be injured or killed from disposal activities is small. 
-50- 

While commercial fishery data cannot provide a reliable estimate of abundance of a species it 

can provide perspective on the relative impact the effects of an action can have at the population 

and species scales. Commercial data for the eulachon fishery on the Columbia River shows an 

average of 122,157 (range 2,160 to 190,555) eulachon caught from 2005 – 2009. Since most 

eulachon in the action area are most likely from the Columbia River, if individuals from a school 

of eulachon were injured or killed by disposed dredged material it would still make up only a 

small portion (likely less than 1%) of the Columbia River population. Therefore, effects on 

population abundance, productivity, distribution, and genetic diversity will not be measurable or 

meaningfully at the population scale. 

2.4.3 Effects to Critical Habitat 

Green sturgeon. The specific critical habitat that will be affected by the interrelated 

actions to the proposed action is the designated critical habitat for green sturgeon in the 

nearshore area of the Pacific Ocean. Designated critical habitat for green sturgeon is identified as 

the Coastal Marine Waters (within 110 meters depth) (Table 1). The habitat features required to 

support successful subadult and adult migration include water quality, food resources, and safe 

passage. This area may also support the maturation of subadults to the adult life stage. Of these, 

water quality, food resources, and safe passage are likely to be affected by the proposed action. 

The impacts are described below. 

1. Water Quality. Suspended sediment levels will be increased over background due to fine 

sediment mobilized by disposal from a hopper dredge transport ship. Suspended sediment 

levels are likely to increase for a short time with the highest concentrations occurring at 

the ship’s disposal point and dispersing from that point depending on ocean currents, 

disposal material size composition, wave action, dredge ship speed, and disposal rate. 

The NMFS predicts suspended sediment will drift approximately 500 feet outside of the 

ODMD sites. It is likely that suspended sediment concentrations generated by dredge 

material disposal will exceed the 17 mg/l effects threshold for injury as described above 

for salmonids, but adult and subadult green sturgeon are less sensitive to suspended 

sediments than salmonids. Green sturgeon inhabit much more turbid environments than 

do salmonids and are more benthic oriented; therefore the NMFS is reasonably certain 

these elevated suspended sediments concentrations will occur primarily in the upper 

water column and the duration of exposure will result in insignificant change to this PCE. 

The EPA’s proposed action includes the adoption and implementation of the SMMP that 

requires any proposed sediments for disposal to adhere to the procedures approved by the 

Regional Sediment Evaluation Team (RSET). Only “clean” dredged material can be 

placed into the ocean under current statutes and regulations. Sediment suitability must be 

documented prior to disposal at the site. Although trace levels of various heavy metals, 

PAHs and other compounds will occur with the sediments, these levels will not exceed 

concentrations harmful to the organisms occupying the action area; therefore disposal of 

this dredge material will not alter the quality and function of this PCE. 

2. Food Resources. Disposal of dredge materials contributes a layer of unconsolidated 

sediment on the ocean floor. In doing this, infaunal and epifaunal invertebrates will be 
-51- 

covered with a layer of sandy sediment. Before the winter storms disperse the material 

some reduction of invertebrates on the ocean floor may occur. The result would be a 

reduction in the food source and habitat available to marine organisms in the area for up 

to 6 or 7 months between the disposal and when the winter storms disperse the material. 

The likely change in prey species is dependent then on the recolonization rate of this area. 

Recolonization is uncertain while the site is in active use for dredged material disposal 

over the 20-year life of the designation. The maximum interval between disposal events 

is approximately one year. Recolonization potential is affected by the interval duration 

between deposition events, particle size, currents, and compaction/stabilization following 

deposition (Newell et al. 1998, Van der Veer et al. 1985). Rates of recovery listed in the 

literature range from several months for estuarine muds, and up to two to three years for 

sands and gravels (Hitchcock et al. 1999). Recolonization may take longer in areas with 

lower current (Van der Veer et al. 1985). This site is indicative of a dynamic nearshore 

ecological zone that naturally would be characterized by a disturbance based ecosystem. 

Disturbance-based ecosystems are indicative of rapid recolonization rates by 

opportunistic organisms tolerant of conditions that are physiologically stressful 

(Pemberton and MacEachern 1997). 

Although conducting feeding studies on green sturgeon have proven difficult, some 

information is available. In addition to various invertebrates, green sturgeon appear to be 

opportunistic foragers and feed on various fish species, such as lingcod (Dumauld et al.

2008), herring (Erickson and Hightower 2007), sand lace and anchovies (Moyle 2002) 

that may also be adversely impacted by the disposal. Similar exposure, avoidance 

response, and risks are likely with forage fish species as were described for the coho 

salmon, green sturgeon, and eulachon. Typically these fish are smaller species and less 

likely to avoid physical harm. The number of individuals prey items impacted is difficult 

to estimate, but NMFS is reasonably certain the number adversely affected would not 

significantly deplete the overall abundance of forage available to green sturgeon. Because 

these impacts to forage base is highly localized, the likely decrease in forage abundance 

is considered insignificant to the total food resources available to green sturgeon. The 

food resources PCE will not be functionally changed. 

3. Safe Passage. Safe passage for green sturgeon is challenged by the physical threat of the 

disposal material. The NMFS concludes some risk to the safe passage of a few younger, 

smaller (2 feet) subadults exists due to this action, but the action: (1) Is limited to 1,722 

acres of the Pacific Ocean; (2) is only temporary; (3) will only affect a few individuals; 

and (4) the amount of migration habitat adjacent to the action area is considerably greater 

than within the action area. Therefore the quality and function of the safe passage PCE 

will not be changed by designating these ODMD sites and the subsequent dredge material 

disposal. 

Information presented in the status and baseline sections of this opinion show that the ocean 

habitat conditions are driven by factors working at a much larger scale than this action area. 

Three PCEs will be affected, but will not be functionally changed because effects will be small 

scale, short term, or unlikely. Since the effects will not adversely change the habitat functions at 
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the site scale, the effects from the proposed project will not impair the ability of critical habitat to 

play its intended conservation role. 

2.5 Cumulative Effects 

 “Cumulative effects” are those effects of future State or private activities, not involving Federal 

activities, that are reasonably certain to occur within the action area of the Federal action subject 

to consultation (50 CFR 402.02). Future Federal actions that are unrelated to the proposed action 

are not considered in this section because they require separate consultation pursuant to section 7 

of the ESA. The NMFS looked in the BA provided by the EPA and did not identify any future 

non-Federal actions that would affect ESA-listed species or critical habitats. 

2.6 Integration and Synthesis

The Integration and Synthesis section is the final step of NMFS’ assessment of the risk posed to 

species and critical habitat because of implementing the proposed action. In this section, we add 

the effects of the action (Section 2.4) to the environmental baseline (Section 2.3) and the 

cumulative effects (Section 2.5) to formulate the agency’s biological opinion as to whether the 

proposed action is likely to: (1) Result in appreciable reductions in the likelihood of both 

survival and recovery of the species in the wild by reducing its numbers, reproduction, or 

distribution; or (2) reduce the value of designated or proposed critical habitat for the 

conservation of the species. These assessments are made in full consideration of the status of the 

species and critical habitat (Section 2.2). 

2.6.1 ESA-listed Species 

After careful review of the effects of the proposed action, species’ status, environmental 

baseline, and cumulative effects (none identified) it is reasonably certain that the proposed action 

will not result in appreciable reductions in survival and recovery of OC coho salmon, green 

sturgeon, and eulachon in the wild by reducing their numbers, reproduction, or distribution. The 

status of OC coho salmon, green sturgeon, and eulachon are such that removal of a small number 

of individuals will not affect the species’ ability to replace or sustain themselves. The 

environmental baseline in the action area is likely currently providing the basic biological needs 

of OC coho salmon, green sturgeon, and eulachon. Disposal activities will occur in a highenergy and dynamic ocean environment where larger scale physical and biological processes 

than the action area control productivity and environmental and baseline conditions. The 

proposed action will not occur on a large enough spatial or temporal scale to significantly change 

productivity and environmental and baseline conditions such that normal behavioral patterns of 

OC coho salmon, green sturgeon, or eulachon would change when in the ocean environment. 

The physical threat to OC coho salmon, green sturgeon, and eulachon from the proposed action 

comes from exposure of these fish to disposed dredged material. The consequences of fish 

exposure to disposed dredged material include injury and death of up to 697 yearling OC coho 

salmon individuals per year. This number will be spread over the Yaquina River, Beaver Creek, 

and Alsea River populations of OC coho salmon and will occur every five to eight years with 

lower numbers of individuals injured or killed in other years. The NMFS is reasonably certain 
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that the effects to abundance and productivity are insignificant at the population scale because 

such a small portion of each population will be affected (approximately 0.28%). The NMFS is 

also reasonably certain that the number of green sturgeon and eulachon injured or killed will be 

low and effects to abundance and productivity at the population scale will be insignificant 

because such a small proportion of the green sturgeon and eulachon populations will be exposed 

to disposed dredged material. 

2.6.2 Critical Habitat 

After review of the effects of the proposed action, environmental baseline, and cumulative 

effects (none identified) NMFS is reasonably certain that the proposed action will not reduce the 

value of designated critical habitat for the conservation of green sturgeon. The action area is not 

designated critical habitat for OC coho salmon or eulachon. The proposed action will affect three 

PCEs of green sturgeon designated critical habitat including water quality, food resources, and 

safe passage. The quality and function of these PCEs in the action area will not significantly 

change as a result of the proposed action because the effects will be localized, short-term, or 

unlikely. Therefore, critical habitat for green sturgeon will retain its ability to play its intended 

conservation role for this species. 

2.7 Conclusion

After reviewing the current status of the listed species, the environmental baseline within the 

action area, the effects of the proposed action, and cumulative effects, it is NMFS’ biological 

opinion that the proposed action is not likely to jeopardize the continued existence of OC coho 

salmon, green sturgeon, or eulachon or to destroy or adversely modify critical habitat designated 

for green sturgeon. 

2.8. Incidental Take Statement 

Section 9 of the ESA and Federal regulations pursuant to section 4(d) of the ESA prohibit the 

take of endangered and threatened species, respectively, without a special exemption. Take is 

defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt 

to engage in any such conduct. Harm is further defined by regulation to include significant 

habitat modification or degradation that results in death or injury to listed species by significantly 

impairing essential behavioral patterns, including breeding, feeding, or sheltering. Incidental take 

is defined as take that is incidental to, and not the purpose of, the carrying out of an otherwise 

lawful activity. For this consultation, we interpret “harass” to mean an intentional or negligent 

action that has the potential to injure an animal or disrupt its normal behaviors to a point where 

such behaviors are abandoned or significantly altered.8

 Section 7(b)(4) and section 7(o)(2) 

 

8

 The NMFS has not adopted a regulatory definition of harassment under the ESA. The World English Dictionary 

defines harass as “to trouble, torment, or confuse by continual persistent attacks, questions, etc.” The U.S. Fish and 

Wildlife Service defines “harass” in its regulations as “an intentional or negligent act or omission which creates the 

likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns 

which include, but are not limited to, breeding, feeding, or sheltering (50 CFR 17.3). The interpretation we adopt in 

this consultation is consistent with our understanding of the dictionary definition of harass and is consistent with the 

Service’s interpretation of the term. 
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provide that taking that is incidental to an otherwise lawful agency action is not considered to be 

prohibited taking under the ESA if that action is performed in compliance with the terms and 

conditions of this incidental take statement. 

2.8.1 Amount or Extent of Take 

The EPA’s proposed action is designating the two Yaquina River ODMD sites pursuant to 

section 102(c) of the MPRSA as amended, 33 U.S.C §§ 1401 to 1445, near the mouth of the 

Yaquina River, Lincoln County, Oregon. The adverse effects identified in this opinion that 

NMFS is reasonably certain will occur are the result of indirect effects of subsequent Federal 

actions carried out by the Corps and other entities carrying out the dredging and disposal of 

dredged material. The EPA expects the two ODMD sites will be used in the future for disposal of 

material dredged by other public or private entities (e.g. the U.S. Coast Guard, Port of Newport, 

Port of Toledo) in accordance with section 201 of the MPRSA. These individual actions are 

likely to cause take of ESA-listed species during dredging and disposal. Therefore, it is more 

appropriate to consider exempting this take on a case-by-case basis as such actions are proposed 

in the future. These disposals would require section 103 permits (which could be multiple-year 

authorizations up to 7 years) from the Regulatory Branch of the Corps and EPA concurrence. 

Individual permits are publicly noticed and require other federal consultation (e.g. ESA, EFH) 

and authorizations (e.g. water quality certification), and EPA’s action here does not authorize 

and will not itself result in disposal of any dredged materials. Therefore, although NMFS 

anticipates indirect effects from EPA’s action, it does not anticipate any take will result from the 

site designation and adoption of the SMMP. Any further analysis of the effects of disposal of 

dredged material at the disposal site and issuance of an incidental take statement with reasonable 

and prudent measures and non-discretionary terms and conditions to minimize take will be 

prepared when an ESA consultation on a dredging and disposal action is requested. 

2.9. Conservation Recommendations 

Section 7(a)(1) of the ESA directs Federal agencies to use their authorities to further the 

purposes of the ESA by carrying out conservation programs for the benefit of the threatened and 

endangered species. Specifically, conservation recommendations are suggestions regarding 

discretionary measures to minimize or avoid adverse effects of a proposed action on listed 

species or critical habitat or regarding the development of information (50 CFR 402.02). The 

following conservation recommendation is a discretionary measure that NMFS believes is 

consistent with this obligation and therefore should be carried out by the Federal action agency: 

1. The EPA should work with the Corps and NMFS to finalize the interagency methodology 

to evaluate the effects of dredging and disposal on ESA-listed species. 

2. The EPA should work with the Corps and NMFS to develop a study to determine the 

seasonal distribution, abundance, and habitat use of salmonids, green sturgeon, eulachon, 

and marine turtles that occur in the nearshore region within and near the contour of 

ODMDS designations. 
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Please notify NMFS if the EPA carries out any of these recommendations so that we will be kept 

informed of actions that are intended to improve the conservation of listed species or their 

designated critical habitats. 

2.10 Reinitiation of Consultation

As provided in 50 CFR 402.16, reinitiation of formal consultation is required where 

discretionary Federal action agency involvement or control over the action has been retained, or 

is authorized by law, and if: (1) New information reveals effects of the agency action on listed 

species or designated critical habitat in a manner or to an extent not considered in this opinion; 

(2) the agency action is subsequently modified in a manner that causes an effect on the listed 

species or critical habitat not considered in this opinion; or (3) a new species is listed or critical 

habitat designated that may be affected by the action. 

2.11 “Not Likely to Adversely Affect” Determinations 

In this biological opinion, NMFS concludes that the proposed action is not likely to adversely 

affect the following species and critical habitats: 

1. LCR Chinook salmon 

2. UCR Chinook salmon 

3. UWR Chinook salmon 

4. SR fall Chinook salmon 

5. SR spring/summer Chinook salmon 

6. LCR coho salmon 

7. SONCC coho salmon 

8. Eastern DPS Steller sea lions 

9. Blue whales 

10. Fin whales 

11. Humpback whales 

12. Southern Resident killer whales 

13. Sei whales 

14. Sperm whales 

15. Green turtles 

16. Leatherback turtles 

17. Loggerhead turtles 

18. Olive ridley sea turtles 

19. Leatherback turtle critical habitat 

2.11.1 ESA-listed Fish Species 

Chinook salmon. LCR, UCR, UWR, SR fall and SR spring/summer run Chinook salmon 

all potentially occur in the action area. Weitkamp and Neely (2002) showed that coded-wire 

tagged adult Chinook salmon from each ESU were recovered in the northern Oregon Coast 

recovery area, which is where the action area is located. Although they potentially occur in the 
-56- 

action area, Chinook salmon will likely be present in low numbers because they are highly 

dispersive once they leave the Columbia River. Adult Chinook salmon potentially would be 

present during disposal activities. It is unlikely that a young Chinook salmon would find itself in 

the nearshore environment away from their natal stream. After most young salmon enter coastal 

waters, their swimming movements are oriented and directed, usually to the northwest toward 

the migration corridor of the Alaska Current although the speed of this migration is affected by 

size of the salmon and the direction and intensity of coastal currents (Pearcy 1992). The NMFS 

concludes the proposed designation of two ODMD sites near Yaquina Bay in the Pacific Ocean 

is NLAA LCR, UCR, UWR, SR fall and SR spring/summer run Chinook salmon for the 

following reasons: (1) Implementation of the SMMP ensures no contaminated sediment will be 

disposed in the ODMD sites; (2) adult and juvenile Chinook salmon presence is discountable 

because they are likely to be using areas further offshore for migration; and (3) adverse impacts 

to the forage base for Chinook salmon are insignificant because the suspended sediment plumes 

are localized and are not expected to reduce the primary or secondary production of the affected 

area. Critical habitat designated for LCR, UCR, UWR, SR fall and SR spring/summer run 

Chinook salmon does not occur in the action area. 

Coho salmon. LCR and SONCC coho salmon potentially occur in the action area and 

may be affected by the proposed designation of ODMD sites near Yaquina Bay in the Pacific 

Ocean. According to Shapalov and Taft (1954), yearling coho salmon enter the ocean and spend 

a few months outside their natal streams before migrating north to far northern waters. During 

this northern migration, yearling coho salmon distribute throughout the continental shelf and 

move further offshore than the nearshore environment of the action area. The NMFS concludes 

that the proposed designation of two ODMD sites near Yaquina Bay is NLAA LCR and SONCC 

because: (1) Presence of adult and juvenile LCR and SONCC coho salmon is discountable 

because they are likely using areas further offshore than the action area for migration; (2) 

implementation of the SMMP ensures no contaminated sediments are disposed of in the ODMD 

sites; and (3) adverse impacts to the forage base for coho salmon are insignificant because the 

suspended sediment plumes are localized and are not expected to reduce the primary or 

secondary production of the affected area. The action area is not designated critical habitat for 

LCR or SONCC coho salmon. 

2.11.2 ESA-listed Marine Mammals 

Steller sea lions, blue whales, fin whales, humpback whales, Sei whales, sperm whales and 

southern resident killer whales may occur in the action area. Blue whales, fin whales, Sei whales, 

and sperm whales are not generally distributed nearshore, and their presence in the action area is 

unlikely. Humpback whales and Southern Resident killer whales may occur nearer to the shore, 

but their presence in the action area is likely infrequent and transitory. Steller sea lion rookeries 

and haul-outs are sufficiently distant from the action area (the nearest Steller sea lion haulout is 

at Seal Rock, at least five miles away from the disposal sites) that any effects to breeding or 

haul-out behavior are unlikely. The proposed action may indirectly affect the quantity and 

quality of prey available to marine mammals (i.e., salmonid prey of southern resident killer 

whales and Steller sea lions) by changes to water quality and physical injury, discussed in detail 

above for OC coho salmon. 
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In the event that marine mammals are present during disposal activities, the proposed action may 

cause temporary disturbance. Vessel transits associated with dredged material disposal (i.e., 

hopper dredge) consist of up to 619 round trips to and from the Yaquina ODMD sites annually. 

Barge-sized vessels, such as a hopper dredge, used for the proposed action would require short 

transits to the nearshore or ODMD sites where the vessel would remain relatively immobile until 

work is complete, with minimal sound or potential for disturbance. Any temporary disturbance 

would be short-term and localized, with no lasting effects, and therefore insignificant. Vessel 

strikes are extremely unlikely because the barge-sized vessels are slow moving, follow a 

predictable course, do not target marine mammals, and should be easily detected and avoided by 

marine mammals. Potential effects from vessel strikes are therefore discountable. 

As described in detail above, EPA adheres to sediment quality standards for open ocean disposal. 

The EPA’s proposed action includes the implementation of the SMMP that requires any 

proposed sediments for disposal to adhere to the procedures approved by the RSET. Only 

“clean” dredged material can be placed into the ocean under current statutes and regulations. 

Sediment suitability must be documented prior to disposal at the site. 

Some marine mammals forage on adult salmon and other prey species (i.e., Southern Resident 

killer whales or Steller sea lions). Up to 697 yearling OC coho salmon may be injured or killed 

annually by disposal activities. Anticipated injury or death of yearling salmonids may result in a 

reduction of adult salmonids available to marine mammals as prey resources, but that reduction 

is insignificant compared to the amount of remaining prey resources available. 

The NMFS is reasonably certain that all potential adverse effects to ESA-listed marine mammals 

are discountable or insignificant and concurs with the EPA’s determination of NLAA for Steller 

sea lions, blue whales, fin whales, humpback whales, sei whales, sperm whales, and southern 

resident killer whales. 

2.11.3 ESA-listed Marine Turtles 

Leatherback sea turtles, loggerhead sea turtles, green sea turtles, and olive ridley sea turtles may 

occur in the action area. These sea turtles are highly migratory, and the life histories of all 

species exhibit complex movements and migrations through geographically disparate habitats, so 

defining their geographic range is difficult. Leatherback, loggerhead, green, and olive ridley sea 

turtles all nest on beaches in the U.S. and all depend on U.S. coastal waters for foraging and 

migratory habitat during certain stages of their life history. However, sea turtles have no 

breeding areas in Oregon and, except for leatherback sea turtles, are extremely rare in Oregon’s 

nearshore habitats. Most leatherback sightings occur in marine waters within the coastal zone. 

Although sightings of sea turtles occur in Oregon, they are, nonetheless, exceptionally rare. The 

probability of their presence in the action area when a disposal event occurs is extremely small. 

Therefore, NMFS finds that all effects of proposed action are reasonably certain to be 

discountable and are NLAA leatherback sea turtles, loggerhead sea turtles, green sea turtles, and 

olive ridley sea turtles. 
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2.11.4 Leatherback Sea Turtle Designated Critical Habitat 

The PCEs that NMFS identified as essential for the conservation of leatherback turtles when it 

designated critical habitat to include marine waters off the U.S. West Coast, including the action 

area, are: (1) A sufficient quantity and quality of their jellyfish prey; and (2) migratory pathway 

conditions that allow for safe and timely passage to, from, and within high use foraging areas, 

including areas within the action area. Dredge disposal activities may result in the loss of polyp 

life-stage jellyfish and adult medusa jellyfish, on the ocean floor and in the water column, 

respectively, in the immediate area where dredge spoils descend through the water column and 

settle on the ocean floor. However, the small amount of prey losses that may occur intermittently 

and in the small area (ODMD site) when dredge spoils are released will result in an insignificant 

reduction in prey available to leatherbacks in their proposed critical habitat. No effects on prey 

quality are anticipated. Similarly, intermittent vessel traffic associated with dredge disposal 

activities would have a discountable effect on leatherback turtle passage through the action area, 

given the extremely unlikely nature of leatherback turtle occurrence in the action area. Therefore, 

NMFS finds that all effects of the action are reasonably certain to be discountable or 

insignificant for designated critical habitat of leatherback turtles. 

3. MAGNUSON-STEVENS FISHERY CONSERVATION AND MANAGEMENT ACT 

The consultation requirement of section 305(b) of the MSA directs Federal agencies to consult 

with NMFS on all actions or proposed actions that may adversely affect EFH. The MSA (section 

3) defines EFH as “those waters and substrate necessary to fish for spawning, breeding, feeding, 

or growth to maturity. Adverse effects include the direct or indirect physical, chemical, or 

biological alterations of the waters or substrate and loss of, or injury to, benthic organisms, prey 

species and their habitat, and other ecosystem components, if such modifications reduce the 

quality or quantity of EFH. Adverse effects on EFH may result from actions occurring within 

EFH or outside EFH, and may include site-specific or EFH-wide impacts, including individual, 

cumulative, or synergistic consequences of actions (50 CFR 600.810). Section 305(b) also 

requires NMFS to recommend measures that can be taken by the action agency to conserve EFH. 

This analysis is based, in part, on the EFH assessment provided by the Federal action agency and 

descriptions of EFH contained in the fishery management plans developed by the Pacific Fishery 

Management Council (PFMC) and approved by the Secretary of Commerce for Pacific Coast 

groundfish (PFMC 2005), coastal pelagic species (PFMC 1998), and Pacific Salmon (PFMC 

1999). 

3.1 Essential Fish Habitat Affected by the Project 

The PFMC described and identified EFH for groundfish (PFMC 2005), coastal pelagic species 

(PFMC 1998), and Pacific Salmon (PFMC 1999). The proposed action and action area for this 

consultation are described in the Introduction to this document (section 1). The action area 

includes areas designated as EFH for various life-history stages of groundfish, coastal pelagics, 

and Pacific salmon (Table 7). There are no habitat areas of particular concern (HAPCs) present 

in the action area. 
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Table 7. Species with designated EFH in the action area. 

Groundfish Species   

 Leopard shark (Triakis semifasciata) Chilipepper (S. goodei) 

 Soupfin shark (Galeorhinus zyopterus) China rockfish (S. nebulosus) 

 Spiny dogfish (Squalus acanthias) Copper rockfish (S. caurinus) 

 Big skate (Raja binoculata) Darkblotched rockfish (S. crameri) 

 California skate (R. inornata) Grass rockfish (S. rastrelliger) 

 Longnose skate (R. rhina) Rougheye rockfish (S. aleutianus) 

 Ratfish (Hydrolagus colliei) Sharpchin rockfish (S. zacentrus) 

 Pacific rattail (Coryphaenoides acrolepsis) Shortbelly rockfish (S. jordani) 

 Lingcod (Ophiodon elongatus) Shortraker rockfish (S. borealis) 

 Cabezon (Scorpaenichthys marmoratus) Silvergray rockfish (S. brevispinus) 

 Kelp greenling (Hexagrammos decagrammus) Speckled rockfish (S. ovalis) 

 Pacific cod (Gadus macrocephalus) Splitnose rockfish (S. diploproa) 

 Pacific whiting (Hake) (Merluccius productus) Stripetail rockfish (S. saxicola) 

 Sablefish (Anoplopoma fimbria) Tiger rockfish (S. nigrocinctus) 

 Aurora rockfish (Sebastes aurora) Vermillion rockfish (S. miniatus) 

 Bank Rockfish (S. rufus) Widow Rockfish (S. entomelas) 

 Black rockfish (S. melanops) Yelloweye rockfish (S. ruberrimus) 

 Blackgill rockfish (S. melanostomus) Yellowmouth rockfish (S. reedi) 

 Greenspotted rockfish (S. chlorostictus) Yellowtail rockfish (S. flavidus) 

 Greenstriped rockfish (S. elongatus) Arrowtooth flounder (Atheresthes stomias) 

 Longspine thornyhead (Sebastolobus altivelis) Butter sole (Isopsetta isolepsis) 

 Shortspine thornyhead (Sebastolobus alascanus) Curlfin sole (Pleuronichthys decurrens) 

 Pacific Ocean perch (S. alutus) Dover sole (Microstomus pacificus) 

 Quillback rockfish (S. maliger) English sole (Parophrys vetulus) 

 Redbanded rockfish (S. babcocki) Flathead sole (Hippoglossoides elassodon) 

 Redstripe rockfish (S. proriger) Pacific sanddab (Citharichthys sordidus) 

 Rosethorn rockfish (S . helvomaculatus) Petrale sole (Eopsetta jordani) 

 Rosy rockfish (S. rosaceus) Rex sole (Glyptocephalus zachirus) 

 Blue rockfish (S. mystinus) Rock sole (Lepidopsetta bilineata) 

 Bocaccio (S. paucispinis) Sand sole (Psettichthys melanostictus) 

 Brown rockfish (S. auriculatus) Starry flounder (Platyichthys stellatus) 

 Canary rockfish (S. pinniger)   

 Coastal Pelagic Species   

 Northern anchovy (Engraulis mordax) Jack mackerel (Trachurus symmetricus) 

 Pacific sardine (Sardinops sagax) Market squid (Loligo opalescens) 

 Pacific mackerel (Scomber japonicus)   

 Pacific Salmon   

 Coho salmon (O. kisutch) Chinook salmon (O. tshawytscha) 
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3.2 Adverse Effects on Essential Fish Habitat

Based on information provided by the EPA and the analysis of effects presented in the ESA 

portion of this document, NMFS concludes that the proposed action will have the following 

adverse effects on EFH designated for Pacific Coast groundfish, coastal pelagic species, and 

Pacific salmon: (1) Water quality degradation due to increased suspended fine sediments for 

younger life stages of EFH species; (2) entrainment and covering of EFH species prey from 

descending sediment plume resulting in short-term reduction of prey; and (3) impacts to safe 

passage through the action area. 

Disposal of dredged material will increase suspended sediment concentrations over background 

due to fine sediment mobilized by a hopper dredge. This will adversely affect water quality in 

the action area. Suspended fine sediment concentrations are likely to increase for a short time 

with the highest concentrations occurring at the ship’s disposal point and dissipating from that 

point depending on current velocities and vectors. Concentrations of suspended fine sediments 

are likely to exceed the 17 mg/l threshold for injury of salmonids in the action area. Although the 

ESA portion of this document determined that effects to primary production in the action area 

from suspended fine sediments were minor, the action area likely contains younger life stages of 

fish (e.g. larvae) with designated EFH that are less tolerant to increases in suspended fine 

sediments that will be exposed to degraded water quality. 

Coarse-grained materials will also be present in disposed dredged material that will fall through 

the water column rather quickly, potentially entraining prey species or covering benthic 

invertebrates that are prey species of fish with designated EFH. Prey for EFH species will likely 

be reduced for a short time within the ODMD sites due to these effects. Disposed dredged 

materials contribute a layer of unconsolidated sediment on the ocean floor that will cover 

infaunal and epifaunal invertebrates. This reduction in food source will likely occur only until 

subsequent winter storms disperse the unconsolidated material. The likely changes in prey 

species are dependent on the recolonization rate of this area. 

Recolonization is uncertain while the site is in active use for dredged material disposal over the 

life of the designation, an indefinite period. The maximum interval between disposal events is 

approximately one year. The length of intervals between deposition events, particle size, 

currents, and compaction/stabilization following deposition affects recolonization potential 

(Newell et al. 1998, Van der Veer et al. 1985). Rates of recovery listed in the literature range 

from several months for estuarine muds, and up to two to three years for sands and gravels 

(Hitchcock et al. 1999). Recolonization may take longer in areas with lower current (Van der 

Veer et al. 1985). This site is indicative of a dynamic nearshore ecological zone that naturally 

would be characterized by a disturbance-based ecosystem. Disturbance-based ecosystems are 

indicative of rapid recolonization rates by opportunistic organisms tolerant of conditions that are 

physiologically stressful (Pemberton and MacEachern 1997). 

Similar exposure, avoidance response, and risks are likely with forage fish species as were 

described for the coho salmon and green sturgeon. Typically, these fish are smaller species and 

less likely to avoid physical injury. Juveniles of larger species are also less likely to be able to 

avoid physical injury. The number of individuals impacted is difficult to estimate, but it is 
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reasonable to conclude the number adversely affected would not significantly deplete the overall 

abundance of forage available to EFH species in the surrounding ocean. Because these impacts 

to the forage base are highly localized, the decrease in forage abundance is considered 

insignificant to the total food resources available to EFH management species. Because impacts 

to prey species, both invertebrate and vertebrate are localized, the food resources in the ODMD 

sites and the EFH will not be functionally changed. 

Safe passage for EFH managed species is challenged by the physical threat of the disposal 

material. Some individuals of the various species will experience effects from the discharge of 

these dredged sediments from the hopper dredge. The exposure of EFH management species to 

the disposal material was determined to be inevitable based on the expectation that the fish will 

not exhibit avoidance behavior from the ship. Larger animals are more likely to successfully 

evade the sediment plume without significant physical injury that would result in death because 

their faster swimming speed allows evasion. The NMFS is reasonably certain some risk to the 

safe passage of younger, smaller specimens exists due to this action, but the action : (1) Is 

limited to 1,722 acres of the Pacific Ocean; (2) is only temporary; and (3) the amount of 

migration habitat adjacent to the action area is considerably greater than within the action area. 

Therefore the safe passage of the EFH managed species will not be functionally changed by 

designating this ODMD sites and the subsequent dredge material disposal. 

3.3 Essential Fish Habitat Conservation Recommendations 

The NMFS expects that full implementation of these EFH conservation recommendations would 

protect, by avoiding or minimizing the adverse effects described in Section 3.2 above, 

approximately 1,722 acres of designated EFH for Pacific Coast groundfish, coastal pelagic 

species, and Pacific salmon.

1. The NMFS recommends that the EPA work with the Corps and NMFS to develop a plan 

for monitoring fish interactions with the disposed dredged materials. 

2. The NMFS recommends that the EPA work with the Corps and NMFS to develop a study 

to determine the seasonal distribution, abundance, and habitat use of EFH species and 

their forage occurring in the nearshore region within and near the contour of ODMD site 

designations. 

3.4 Statutory Response Requirement

As required by section 305(b)(4)(B) of the MSA, the Federal action agency must provide a 

detailed response in writing to NMFS within 30 days after receiving an EFH Conservation 

Recommendation from NMFS. Such a response must be provided at least 10 days prior to final 

approval of the action if the response is inconsistent with any of NMFS’ EFH Conservation 

Recommendations, unless NMFS and the Federal action agency have agreed to use alternative 

time frames for the Federal action agency response. The response must include a description of 

measures proposed by the agency for avoiding, mitigating, or offsetting the impact of the activity 

on EFH. In the case of a response that is inconsistent with NMFS Conservation 

Recommendations, the Federal action agency must explain its reasons for not following the 

recommendations, including the scientific justification for any disagreements with NMFS over 
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the anticipated effects of the action and the measures needed to avoid, minimize, mitigate, or 

offset such effects, 50 CFR 600.920(k)(1). 

In response to increased oversight of overall EFH program effectiveness by the Office of 

Management and Budget, NMFS established a quarterly reporting requirement to determine how 

many conservation recommendations are provided as part of each EFH consultation and how 

many are adopted by the action agency. Therefore, we ask that in your statutory reply to the EFH 

portion of this consultation, you clearly identify the number of conservation recommendations 

accepted. 

3.5 Supplemental Consultation

The EPA must reinitiate EFH consultation with NMFS if the proposed action is substantially 

revised in a way that may adversely affect EFH, or if new information becomes available that 

affects the basis for NMFS’ EFH conservation recommendations, 50 CFR 600.920(l). 

4. DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW 

Section 515 of the Treasury and General Government Appropriations Act of 2001 (Public Law 

106-554) (Data Quality Act) specifies three components contributing to the quality of a 

document. They are utility, integrity, and objectivity. This section of the opinion addresses these 

Data Quality Act (DQA) components, documents compliance with the DQA, and certifies that 

this opinion has undergone pre-dissemination review. 

4.1 Utility: Utility principally refers to ensuring that the information contained in this 

consultation is helpful, serviceable, and beneficial to the intended users. The intended user is the 

EPA. 

An individual copy was provided to the EPA. This consultation will be posted on the NMFS 

Northwest Region website (http://www.nwr.noaa.gov). The format and naming adheres to 

conventional standards for style. 

4.2 Integrity: This consultation was completed on a computer system managed by NMFS in 

accordance with relevant information technology security policies and standards set out in 

Appendix III, ‘Security of Automated Information Resources,’ Office of Management and 

Budget Circular A-130; the Computer Security Act; and the Government Information Security 

Reform Act. 

4.3 Objectivity: 

Information Product Category: Natural Resource Plan. 

Standards: This consultation and supporting documents are clear, concise, complete, and 

unbiased; and were developed using commonly accepted scientific research methods. They 

adhere to published standards including the NMFS ESA Consultation Handbook, ESA 
-63- 

Regulations, 50 CFR 402.01, et seq., and the MSA implementing regulations regarding EFH, 50 

CFR 600.920(j). 

Best Available Information: This consultation and supporting documents use the best 

available information, as referenced in the Literature Cited section. The analyses in this 

Opinion/EFH consultation contain more background on information sources and quality. 

Referencing: All supporting materials, information, data and analyses are properly 

referenced, consistent with standard scientific referencing style. 

Review Process: This consultation was drafted by NMFS staff with training in ESA and 

MSA implementation, and reviewed in accordance with Northwest Region ESA quality control 

and assurance processes. 
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